Full text of "Atari_400-800_Service_Manual"

ATARI HOME COMPUTER FIELD SERVICE MANUAL 4 0/S ATARI believes that the information described in this manual is accurate and reliable, and much care has been taken in its preparation. However, no responsibility, financial or otherwise, shall be accepted for any consequences arising out of the use of this material. Information contained herein is subject to change. Revisions may be issued to advise of such changes and/or additions. Correspondence regarding this document should be forwarded to Manager of Technical Support, Consumer Product Service, ATARI, Incorporated, 1312 Grossman Road, Sunnyvale, CA 94086, U.S. America. TABLE OF CONTENTS Section Title Page INTRODUCTION ix 1 THEORY OF OPERATION l-I Overview l-l User Interface 1-2 *00/S00 Mechanical Description 1-3 Motherboard 1-4 Central Processing Unit 1-5 ROM Personality PCB 1-5 RAM PCB 1-5 Keyboard 1-6 Power Supply 1-6 Program Cartridge 1-6 *00/800 Electronic Discussion 1-7 Central Processing Unit 1-7 CPU 6502 Integrated Circuit 1-7 Alphanumerical Television 1-S Interface Controller Color Television Interface 1-10 Adaptor Grcphic Television Interface 1-10 Adaptor I/O Decoder 1-10 Composite Video 1-10 Motherboard Console - *00 l-l 1 Pot Keyboard Integrated 1-11 Peripheral Interface Adaptor I -1 1 Key-In Key-Out Integrated 1-12 Circuit Memory Map Decoder 1-12 I/O Decoder 1-13 Motherboard Console - 800 1-U Bi-directional Data Buffer l-U ROM Personality Board 1-15 Power Supply 1-16 ROM Cartridge 1-17 Accessories 1-17 AC Power Adaptor 1-17 TV Switch Box 1-17 'BASIC Program Cartridge 1-17 2 SILKSCREEN AND SCHEMATICS 2-1 3 TROUBLESHOOTING AND TESTING 3-1 Overview 3-1 Tests ^ 3-1 Equipment Needed 3-1 Testing With and Without 3-2 the SALT II Cartridge ATARI Home Computer iii TABLE OF CONTENTS (Cont) Section Title Page Overview of Tests 3-2 Power -Up Test 3-2 Keyboard Test 3-2 RAM and ROM Test 3-2 SALT n Menu 3-5 Color Bar Test 3-6 Any Video Test 3-7 Gray Bar Test 3-S Keyboard Test , . . . » 3-9 Switch Test 3-9 Tone Test 3-9 Display Options 3-10 Port Test 3-10 Verify ROM Test = 3-11 RAM Test 3-12 M Test . . .-•. 3-15 Star Raider Test 3-16 Shake Test 3-16 Bumin 3-16 Description of the Other Functions 3-17 Production Test 3-17 Boot B 3-17 Examine 3-17 Adjust 3-17 Summary 3«1 7 if DISASSEMBLY/ ASSEMBLY MAINTENANCE i^-i ATARI *00 Home Computer Console - Disassembly .»..,.. ^1 Keyboard and Power Supply Access « if-1 Keyboard Removal if-3 Power Supply Removal ti~4 CPU, RAM and Motherboard Access ^6 CPU and RAM Removal if-6 ATARI 800 Home Computer Console - Disassembly ^-S Access to RAM Boards and if-S ROM Board Access to Power Supply and ^9 Keyboard Assembly Remove Top Cover if-9 Remove the PCB Module ^-10 Remove the Power Supply „ . . i^-i 1 Access to CPU Printed Circuit Board if-1 2 Access to Motherboard ^-13 Keyboard Removal i^-l /f ATARI Home Computer iv TABLE OF CONTENTS (Cont) Section Title Page ATARI WO Home Computer Console - Assembly ^15 Module Assembly Reassembly it~l5 Keyboard Installation *-I6 Power Supply Installation ^^-16 Top Cover Installation i^-17 ATARI 800 Home Computer Console - Asc^mbly H~i7 Keyboard Assembly ^17 Motherboard Installation , i^-^7 CPU PCB Installation i^-lS Power Supply Installation *-l 8 Module Assembly Installation Into Top Cover *-19 Bottom Cover Installation t^iS RAM and ROM Installation *-20 Cartridge Door Assembly f^-20 PCB Contact Cleaning and Lubricating ^20 Tools Required i^-20 Procedure ^21 Visual Inspection f^-21 5 WO DIAGNOSTIC FLOWCHARTS 5-1 6 WQ/800 SYMPTOM CHECKLIST 6-1 7 800 DIAGOSTIC FLOWCHARTS 7-1 8 GAME CONTROLLERS 8-1 Joystick (X-Y Controller) S-i Joystick (X-Y ControUer) Check 8-3 Equipment Needed 8-3 Procedure 8-3 Game Paddle 8-4 Game Paddle Controller Check 8-5 Equipment Needed 8-5 Procedure 8-5 9 PARTS LIST g.l *00 Computer 9-2 800 Computer 9_7 10 SERVICE BULLETINS lO-l ATARI Home Computer LIST OF ILLUSTRATION Figure Title " Page 1-1 ATARI *00 Home Computer Console 1-1 1-2 ATARI 800 Home Computer Console 1-2 1-3 MPU Pin Assignments 1-8 i-4 ANTIC Pin Assignments 1-9 1-5 CTIA/GTIA Pin Assignments 1-10 1-6 POKEY Pin Assignments l-ll 1-7 PIA Pin Assignments 1-12 1-8 WO Motherboard Flow Diagram 1-18 1-9 *00 Power Supply 1-19 I-IO 800 Motherboard Flow Diagram 1-20 1-1 1 800 Power Supply Flow Diagram 1-21 1-12 800 Personality Board 1-22 1-13 CPU Board Flow Diagram 1-23 I-U 8K Dynamic RAM Flow Diagram 1-2^ 1-15 16K Dynamic RAM Flow Diagram 1-25 1 -1 6 Game Cartridge Flow Diagram 1-26 1-17 ATARI Home Computer System 1-27 Block Diagram 2-1 WO Motherboard Siikscreen 2-3 2-2 *00 Motherboard Schematic 2-4 2-3 400 Power Supply Siikscreen 2-6 2-^ *00 Power Supply Schematic 2-7 2-5 800 Motherboard Siikscreen 2-9 2-6 300 Motherboard Schematic 2-10 2-7 800 Power Supply Siikscreen 2-12 2-8 800 Power Supply Schematic 2-13 2-9 800 Personality Board Siikscreen 2-U 2-10 800 Personality Board Schematic 2-15 2-1 1 CPU Board Siikscreen 2-16 2-12 CPU Board Schematic 2-17 2-13 8K RAM Board Siikscreen 2-18 2-U 8K RAM Board Schematic 2-19 2-15 16K RAM Board Siikscreen 2-20 2-16 16K RAM Board Schematic 2-21 3-1 Special Graphics Test 3-3 3-2 SALT Header 3-/* 3-3 SALT II Menu 3-5 3-A Color Bar Test Screen 3-6 3-5 Any Video Test Screen 3-7 3-6 Gray Bar Test Screen 3-8 3-7 Port Test Screen 3-10 3-8 RAM TEST Screen 3-13 ATARI Home Computer vi LIST OF ILLUSTRATION (Cont) Figure Title Page *-l ATARI *00 Console, Bottom Cover Screw Location *-2 ^-2 ATARI *00 Console, Top Cover Removal *-3 *-3 ATARI *00 Console, Keyiaoard Removal *-4 *-* ATARI *00 Console, Power Supply Removal ^5 *-5 ATARI *00 Console, Module Assembly *-7 *-6 ATARI 800 Console, Cartridge Door - *-9 Assembly Removal ^'7 ATARI 800 Console, Bottom Cover Removal i^-10 if-S ATARI 800 Console, Module Assembly Removal *-l 1 *-9 ATARI 800 Console, Power Supply Removal (^-12 if-lO ATARI 300 Console, CPU Printed Circuit - *-13 Board Removal 'f-l 1 ATARI 800 Console, Motherboard Removal ^--15 *-12 ATARI 800 Console, Keyboard Removal ifr-l5 5-1 Keyboard Connection Chart 5-38 5-2 Defective RAM Boards 5-39 7-1 Keyboard Connection Chart 7-38 7-2 Defective RAM Boards 7-39 8-1 Joystick (X-Y ControUer) 8-2 8-2 Joystick Schematic 8-3 8-3 Game Paddle 8-4 8-4 Game Paddle Schematic 8-5 LIST OF TABLES Table Title Page 1 -I Memory Map Selected Lines 1-13 1 -2 I/O Decoder Select Line 1-14 3-1 Port Test Legend 3-12 3-2 Defective RAM Boards 3-U 3-3 Defective RAM Identified 3-15 5-1 Clock Circuit 5-36 5-2 Defective RAM Boards 5-39 5-3 Port Test Legend 5-40 7-1 Clock Circuit 7-36 7-2 Defective RAM Boards 7-39 7-3 Port Test Legend 7-40 ATARI Home Computer vii INTRODUCTION The ATARI ^00/800 Home Computer"^^ Field Service Manual is organized in 10 Sections: i THEORY OF OPERATION - overview of how the *00 and 800 Home Computers work- 2 SILK5CREEN5 AND SCHEMATICS - electrical layouts and drawings for major components. 3 TESTING AND TROUBLESHOOTING - overview of tests which assist in diagnosing malfunctions. * DISASSEMBLY/ASSEMBLY - detaUed instructions to completely disassemble and assemble both units. 5 WO DIAGNOSTIC FLOWCHARTS - detailed procedures for troubleshooting and repairing the *00 Computer. 6 *00/800 SYMPTOM CHECKLIST - quick reference for troubleshooting each computer. 7 800 DIAGNOSTIC FLOWCHART - detailed procedures for troubleshooting and repairing the 800 Computer. 8 GAME CONTROLLERS - overview of hand controller construction and recommended test procedures. 9 PARTS LIST - detailed breakdown of all parts used in each unit. 10 SERVICE BULLETINS - section to be used to hold Field Change Orders, Upgrade Bulletins, and Tech Tips. This manual is designed for use by both the experienced and inexperienced service technician. The Diagnostic Flowcharts (Sections 5 and 7) provide detailed diagnostics and repair procedures for technicians not completely familiar with the ATARI *00/800 Home Computers. The Symptom Checklist (Section 6) provides a rapid repair reference for the more experienced technician. ATARI Home Computer ix SECTION I THEORY OF OPERATION OVERVIEV The Atari *00 Computer Home Console contains the central processor unit (CPU) and memory in the form of the Operating System (read-only-memory (ROM)) and 8K or 16K of user programmable random access memory (RAM). The console contains the keyboard, cartridge slot, controller jacks, and serial input/output (I/O) port for connecting peripheral devices (see Figure l-U. rawci oNforr SWITCH KiirmsAL CONNECTOa JACK SYSTIM RESET SWITCH Figure 1-1. ATARI ^00 Home Computer Console ATARI Home Computers 1-1 The ATARI 800 Home Computer Console contains the CPU and memory in the form of the Operating System (iOK of read-only-memory (ROM)) and SK to i6K (standard) of user programmable random access memory (RAM); plus two expansion sockets for additional RAM modules (maximum ^8K). The console also contains the keyboard, cartridge slots (2), controller jacks and a serial I/O port for connecting peripheral devices (see Figure 1-2). HAND CONTtOUn tACKS SYSTEM HSCT SWITCM Figure 1-2. ATARI 800 Home Computer Console USER INTERFACE The ATARI *00/8G0 Home Computer Consoles are general purpose microcomputers using the 6502 microprocessor. The ATARI i^OO/800 Consoles are the central processing units for their respective systems. Each console comes standard with a built-in typewriter style keyboard, 8K/16K of RAM, ROM operating systems, connector jacks for adding peripherals and hand controllers, and a 15-foot Radio Frequency (RF) cable for connection to the user's television set. The controller jacks on the front of both consoles accepts the X-Y (joystick) and paddle hand controllers available from ATARI. ATARI Home Computers 1-2 The right side panel of the Atari *00 Computer Console contains a peripheral jack, power ON/OFF switch, and a power jack. The channel 2/3 switch is located on the back of the console. This switch changes the console transmission frequency to either channel 2 or channel 3 (refer to Figure 1-1). The right side panel of the Atari 800 Home Console contains a monitor jack, a peripheral jack, a channel 2/3 switch, a power ON/OFF switch, and a power jack (refer to Figure 1-2), Both Console keyboards provide a full alphanumeric character set, cursor controls, and special purpose keys- The alpha keys when used in conjunction with the Control (CTRL) key become special graphic symbols. To the right of the keyboard is the power ON light and four special control keys (refer to Figure 1-1 and Figure 1-2). From the top to the bottom they are: SYSTEM RESET - Interrupts whatever the computer is doing and restarts the Operating System or Program Cartridge. OPTION - Interrupt used by the Program Cartridge to choose among the variations within a game or program. SELECT - Interrupt used to select one of several games or programs on the Program Cartridge. START - Interrupt used to Start the game or program selected from the Program Cartridge. »00/800 MECHANICAL DESCRIPTION The Atari WO/SOO Computer Home Consoles are made up of seven major functional modu es they are: Motherboard Central Processing Unit (CPU) Printed Circuit Board ROM Personality Printed Circuit Board (Operation System) (300 Only) RAM Printed Circuit Board(s) Keyboard Power Supply Board Program Cartridge ATARI Home Computers 1-3 The Printed Circuit Boards (PCBs) piug into sockets on the motherboard, using a common Address Bus, Data Bus and clock lines. The various power requirements are routed from the power supply through the motherboard to all printed circuit boards. The keyboard connects directly to the motherboard through a ribbon connector. The sixteen-Une Address Bus allows the microprocessor to directly address 64K of memory. The eight-line Data Bus provides the communication and data path between the functional modules. Figures 1-8 thru 1-17 at the end of this section provide function block diagrams of PCBs in the *00/800 systems. Motherboard The motherboard ties all components of the computer system together. It also performs a variety of logic functions. All PCBs and connector cables plug into the motherboard and allow communication between the functional blocks of the '^OO and SOO Computer Consoles. The motherboard also performs the following: • Generates a 3.58 MHz master clock for the Central Processing Unit's PCB. • Generates the Power -ON RESET for the Central Processing Unit PCB and the peripherals. • Provides the driving circuitry for the Key-Press signal from the Central Processing Unit PCB to the Console speaker. • Converts signals from the various hand controllers into recognizable data for the microprocessor. • Buffers and drives the data lines between the Central Processing Unit PCB, the RAM PCBs, and the remainder of the system. • Does the first memory map decoding of the possible 64K address locations into 8K blocks for the microprocessor. • Generates control signals for the peripheral devices. • Receives video data from the Central Processing Unit PCB, converts it into a composite video and routes it to the power supply PCB. • Combines the sound from the Computer system and the audio track of prerecorded cassettes. • Develops the sound subcarrier for the television audio as part of the composite video. ATARI Home Computers 1-^ Central Processing Unit The Centrai Processing Unit (CPU) PCB is the controller of the entire Console system. The CPU PCB contains the 6502 microprocessor, and the ANTIC and CTIA (or GTIA) chips. The CPU PCB controls the Console system and its peripheral devices through address lines (to select which device it needs to communicate with) and data lines (to transmit and/or receive data from a selected device) common to the entire system. Operating instructions for the microprocessor come from the ROM Operating System on the Personality PCB, Additional functions of the CPU PCB are: • deceives the master clock from the motherboard and generates Phase 1 (/I or Ph 1) and Phase 2 (/2 or Ph 2) clocks used to synchronize the entire system. • Transmits a REFRESH signal at least every 2 miliseconds to refresh the dynamic RAM chips on the RAM PCB(s). • Receives the four TRIGGER lines from the fire button on each of the hand controller accessories. • Receives the lines from the four control switches located to the right of the keyboard- • Generates video signals to be processed by the motherboard before they are sent to the RF module on the Power Supply PCB. ROM Personality PCB The ROM Personality PCB contains information in Read-Only Memory (ROM), the program of operating instructions for the microprocessor. Two *K ROMs contain the Operating System, and one 2K ROM contains the arithmatic functions used for BASIC programming. Information is retrieved from the ROMs by addressing a particular location on the ROM using the Address Bus. The data contained at that location is placed on the Data Bus to be read by the microprocessor. The ROM Personality PCB also provides the CHIP SELECT signals used to select LSI chips throughout the Console system and for the bi-directional data buffers on the motherboard. RAM PCB The Random Access Memory (RAM) PCB performs the function of temporary data storage for the system. The RAM is dynamic, requiring REFRESH, and is available in SK or 16K versions. Each RAM chip on the RAM PCB has only seven address lines. To address 16K locations requires U address lines. To accomplish this, a I*-bit address is ATARI Home Computers 1-5 sent to the address demultiplexer, which first passes the lower seven bits to the RAM chips as a Row Address. After an appropriate delay, the highest seven bits are passed as a Column Address. Data is then either put into or taken out of the location selected. The direction of data flow is determined by the Read/Write line. REFRESH occurs at least every two milliseconds. The REFRESH signal is generated on the CPU Board. Keyboard The typewriter-style keyboard is used to generate alphanumeric characters as well as special graphic symbols. The keyboard allows the operator to communicate with the console system for writing programs or responding to preprogrammed cassettes or cartridges. The keyboard consists of 57 normally open switches. The switches are scanned at a rapid rate and when a switch is found closed, that scan pattern is sent to the Pot Keyboard Integrated Circuit (POKEY) for encoding. Power Supply The Power Supply PCB receives 9VAC from an external power adaptor (transformer) and provides +5Vdc, +12Vdc, and -5Vdc for the Console system. The Power ON/OFF switch is mounted on the Power Supply PCB and removes input power by opening the 9Vac lines. An interlock switch breaks power to the system when the operator opens the top panel of the Console to install or remove Program Cartridges. The RF Module resides on the Power Supply PCB, The RF Module generates the RF output for the video screen from the composite video signals received from the motherboard, and is switchabie to television channel 2 or 3, Voltages: +5Vdc A - Supply voltage for the logic PCBs. ■t-5Vdc B - Specially filtered for the video circuitry, +12Vdc and -5Vdc - Supply voltage for the dynamic RAM chips. Program Cartridge The Program Cartridge permanently stores the microprocessor instructions for a particular application. It consists of two i^K ROM chips mounted on the enclosed PCB, Information is received from the ROM chips by addressing the memory locations assigned to the Program Cartridge slot(s). Data in the memory locations is then placed on the Data Bus lines. ATARI Home Computers 1-6 400/800 ELECTRONIC DISCUSSION The remainder of this section provides a detailed discussion of the functions of the seven major modules. Central Processing Unit The Central Processing Unit (CPU) PCB contains the 6502 CPU (or MPU) chip (A303), t^c CTIA or GTIA chip (A301), the ANTIC chip (A3a2), tri-level address buffers (Z303 and Z304), and the clock generator (Z302A and Z302B). CPU 6502 Integrated Circuit The 6502 microprocessor contains register flags, interconnections, arithmetic logic, and control logic, all recognized operation codes. The characteristics of the 6502 microprocessor ares Byte-oriented structure 151 opcodes Decima' and binary arithmetic modes Seven addressing modes True indexing Stack pointer Two interrupt levels 64K address range Integral clock circuit Single +5 volt dc power requirement Figure 1-3 is an illustration of the 6502 pin assignments. The functions of the pins are explained on the following pages. ATARI Home Computers 1-7 vss C i RDY C 2 ^I c > IS^ c* N.C C' NMI q* YP*C c 7 vcc e: S A« e: 9 Al c 10 Aa ■ c a A3 n 12 A« c 13 A3 c It At c 15 A7 i: IC AS n 17 A9 c IS AlO L l» All L 20 MCSfiMZ to J RES 39 3 h 3S 3 SO 37 J ^(IN) 36 3 N.C 33 3 N.C 3* 3 R/V 33 3 at 32 3 Dl 31 3 02 30 3 03 « J D* 21 3 05 27 3 D6 26 3 07 23 3 AI2 2* 1 AI3 23 1 Alt 22 1 1 A13 21 [ 1 VSS Figure 1-3. MPU Pin Assignments Alphgtnumenc Television Interface Controller The primary function of the Alphanumeric Television Interface Controller (ANTIC) chip is to fetch data from memory, independent of the processor, for display on the video screen. Figure 1-4 is an illustration of ANTIC Pin Assignments. ATARI Home Computers 1-8 GROUND VSS CTIA Data ANJJ CTIA Data AN I Light Pen EP CTIA Data AN2 Interrupt Input RNMl Interrupt Output NMl Refresh REF HALT HATt Address Bus A3 Address Bus A2 Address Bus Al Address Bus AH Read/Write R/W Ready RDY Address Bus AlO Address Bus A12 Address Bus A13 Address Bus AH Address Bus A15 *0 D* Data Bus 39 D5 Data Bus 38 D6 Data Bus 37 07 Data Bus 36 ft^ Reset 35 FPhJf Fast Phase C 3* Phtf Phase Clock 33 D3 Data Bus 32 D2 Data Bus 31 Dl Data Bus 30 D^ Data Bus 29 Ph2 Phase 2 Clock 23 A4 Address Bus 27 A5 Address Bus 26 A6 Address Bus 25 A7 Address Bus 2* AS Address Bus 23 A9 Address Bus 22 All Address Bus 21 VDD 5V Power Figure 1-^. ANTIC Pin Assignments ATARI Home Computer I -9 Color Television Interface Adaptor The Color Television Interface Adaptor (CTIA) chip retrieves graphics data from memory vU the ANTTC DMA process- This data is routed to the CTIA eraohics registers. Figure 1-5 illustrates the pin assignments for the CTIA and GTIA, Address Bus Address Bus Ground Data Bus Data Bus Data Bus Data Bus Trigger Trigger 1 Trigger 2 Trigger 3 Console Sw Console Sw 1 Console SW 2 Console SW 3 PAL Color Delay Color Delay Alphanum. Data Alphanum. Data 1 Alphanum. Data 2 Al 1 A^ 2 V5S 3 D3 4 D2 5 Dl 6 00 7 T^ S Tl 9 T2 10 T3 11 5^ 12 SI 13 S2 1* S3 13 PAL 16 DEL 17 ANO IS ANl 19 AN2 20 *0 A2 39 A3 38 A* 37 D* 36 D5 35 D6 3* D7 33 R/W 321 C5I 31 CS2 30 PH2 29 FPHO 23 OSC 27 VDD 26 hAlT 25 - CSYNC 21- LUM2 23 LUM 1 22 LUM 2 21 COL Address Bus Address Bus Address Bus Data Bus Data Bus Data Bus Data Bus Read/Write Chip Select 1 Chip Select 2 Phase 2 Input Clock Out Oscillator Input Power HALT Output Sync Luminance 2 Output Luminance 1 Output Luminance Output "Color Figure 1-5. CTTA/GTIA Pin Assignments Graphics Television Interface Adaptor The Graphic Television Interface Adaptor (GTIA) is an extended capabilities version of the CTIA, having additional high-resolution modes- I/O Decoder The I/O Decoder integrated circuit (ZiOl) is a one-eight decoder demultiplexer. The Iv^?^®^®^ " ** ^"^*^ '^ *® *^° ^<^ 200' but is labeled ZlOl in the 800 Console and Z1Q5 in the WO Console. Composite Video J^^.'tP^T ,^? ^.°° Motherboards route the Composite video signals (COMP CHROMA, COMP LUM, MOD, and COMP VIDEO) to the Power Supply to build the RF videtJ output. ATARI Home Computers 1-10 Motherboard Console - ^QO The *00 Console Motherboard contains the Pot Keyboard (POKEY) (AiOl) chip , the Peripheral Interface Adaptor chip (PIA) (A102), the ROM Personality chips {A1Q3 thru A105), the Keyboard Key-In/Key-Out analog multiplexers, the Memory Map Decoder (Z103), the controller jacks (JlOl thru JIO*), the CPU connector jack (JllO), the Keyboard connector jack, RAM connectors and Cartridge connectors- Pot Keyboard Integrated Circuit The Pot Keyboard Integrated Circuit (POKEY) provides the Interface between the Keyboard, the Serial I/O ports, and the microprocessor. It also contains four semi- independent audio channels, each with its own frequency, noise, and volume control. Figure i-6 shows the pin assignments of the POKEY. Ground Data Bus Data Bus Data Bus Data Bus Data Bus Phase 2 Clock Put Scan Pot Scan Pot Scan Pot Scan Pot Scan Pot Scan Pot Scan Pot Scan Keyboard Scan 5 V Power Keyboard Scan Keyboard Scan Keyboard Scan VSS D3 D* D3 06 D7 02 P6 P7 P* P5 P2 P3 PO PI K^ VDD kJ K3 *0 D2 39 Di 3S DO 37 AUDIO 36 AO 35 Al 34 A2 33 A3 32 R/W 31 CSl 30 CSQ 29 IRQ 28 SOD 27 OCLK 26 BCLK 25 KRl 2* SID 23 KO 22 m 21 K2 Data Bus Data Bus Data Bus Audio Out Address Bus Address Bus Address Bus Ac^iiress Bus Read/Write Control Chip Select Chip Select Interrupt Request Serial Output Data Serial Output Clock Bidirectional Clock Keyboard Scan Serial Input Data Keyboard Scan Keyboard Scan Keyboard Scan Figure 1-6. POKEY Pin Assignments Peripheral Interface Adaptor The Peripheral Interface Adaptor (PIA) (6520) has two 8-bit programmable I/O ports and two control bits for each port, for a total of ten lines per port. Figure 1-7 shows the pin assignments of the PIA. ATARI Home Computers l-ll ^ l— PAT fc 2 PAl c 3 PA2 c * P« c 5 PA* c « PW c 7 PA« q S p^r 9 10 PBI c n PB2 c 12 PBS c 13 PB« c 1« PM c 1^ PW c 1« PB7 17 IS ■L -c 1» vcc m ■ c: 20 MCSU20 40 39 3S 37 3« 33 3* 33 32 31 30 2f 2S 27 2S 23 2* 23 22 21 n** — ^cAi ^ ■ »• CA2 —J , „„ ^ iR^ 3 ^ iRQB 3 -^ RSI n-* M» > 3 J. 1 3 n 3 3 3^ 3-»- 3^ 3^ 3^ DO Dt D2 D3 D* D3 Dt 07 ENABLE CSl CS2 R/ir Figure 1-7. PIA Pin Assignments Key- In Key-Out Integrated Circuits These two *051 (ZlOl and Z102) integrated circuits are used to scan the Keyboard for input data on the '^00 and 800 Computer Consoles. The *051 integrated circuits are analog multiplexers controlled by the input lines A, B, C and X. Memory Map Decoder The Memory Map Decoder integrated circuit (Z103) on the 400/800 Motherboard is a one-of-ten decoder. Four input lines (pins 12, 13, and U, and 15) determine which output line is selected. The 400/800 Computer Console uses only three of the input lines (pins 13, 14, and 15 and pin 12 being grounded) for a total of eight selected output lines (SO -S7), Refer to Table l-I for the line selected for each input combination. ATARI Home Computers 1-12 Table 1-1 Memory Map Selected Lines Signal -Grd A15 Al* A13 Active Pin - 12 13 14 15 Line Device L L L L 1-SO 8K RAM BLOCK L L L H 2 -SI 8K RAM BLOCK L L H L 3-S2 8K RAM BLOCK L L H H *-S3 8K RAM BLOCK L H L L 5-S* 8K RAM/CARTRIDGE L,R L H L H 6-S5 8K RAM/CARTRIDGE L L H H L 7 -56 2K ROM L H H L 7-S6 I/O DECODER (Z105) L H H H 9-S7 *K ROMs (2-"E" <Jc "A") I/O Decoder The I/O Decoder integrated circuit (2105) is a one-of-eight decoder /demultiplexer. The I/O Decoder is used to select the different output devices, such as PIA chip, ^^*^^y/^^P ^^ ^^« ^'^*^/*^T^A chip. Only four of the possible output selections are used. (See Table 1-2.) The I/O Decoder Is enabled by inputs on pins *, 5, and 6; pin * input coming from the Memory Map Decoder (S6), pin 5 input coming from the Address Bus and pin 6 input coming from the Chip Select (CS) line. The Binary Decode is provided by the Address Bus (A08, AQ9 and AlO), ATARI Home Computers 1-13 Table 1-2 I/O Decoder Select Line Enable Binary Decode A12 All Pin 6 6 S6 4 AIG 3 1 A59 2 AS 1 Active Pin Device Selected H L L L L L YO-15 CTIA H L L L L H U Not used H L L L H L Y2-13 POKEY H L L L H H Y3 -12 PIA H L L H L L 11 Not Used H L L H L H Y5-10 9 External Select Not Used Not Used Motherboard Console - 800 Read descriptions provided in Motherboard Console - 400, for items similar in both the i^00 and SOO Console Motherboards- The following paragraphs describe those items unique to the 800 Console Motherboard. The 800 Console Motherboard contains the POKEY chip (AiOl), the PIA chip (A102), /^?n'!^f^'^^^ Key-In/Key-Out analog multiplexers (2103 and 2104), the I/O Decoder -nn? ' S^-^i^^c^ional Data Buffers (2105 and 2106), the controUer jacks (JlOl thru M.nJ' 5 Jj^n^Jj^^*""^ connector jack (3106), the left and right Program Cartridge jacks ^ S^^^^^.^l^^L^^*" ^^^ connector jaci' (JlOl), the ROM Personality connector jack U107J, and the RAM Memory connector jacks (3102, J103, and JiQi^), See Fieures 1-1 1 and 1-12. * Bi-directional Data Buffer The Bi-directional Data Buffers (Z105 and Z106) are 74LS243 quad transceivers, commonly referred to as tri-level buffers. Tri-level refers to the three levels that can occur in the device; the first level pin 1 going high and pin 13 staying low, allows data to tlow through the data buffer in the direction of the CPU; the second level, pin 13 going high and pin 1 staying low, allows data to flow through the data buffer in the direction of the POKEY chip, the PIA chip and the Personality PCB; the third level, with pin 1 and pin 13 both staying low, creates a high impedance condition in the data buffers and allows other devices to transmit data on the Data Bus lines. This high impedance state also isolates the CPU and the RAM PCB from noise generated from a device using the Data Bus lines. ATARI Home Computers 1-U ROM Personality Board The ROM Personality printed circuit board plugs into connector Jack 3107 and occupies memory locations D800 thru FFFF. The Personality board contains the operating system on three ROM chips, two 4K chips and one 2K chip (see Figures 1-13 and 1-U). The two *K ROM chips (A^Ol and A403) contain the I/O subsystem, interrupt processing, initialization Power-Up and Reset. The 2K ROM chip (AW2) contains the floating point arithmetic package. • I/O Subsystem The I/O subsystem contained in the ROM Operating System provides a high-level interface between the user programs and the Console and peripheral hardware. All peripheral devices capable of dealing with character data have symbolic names (such as K, D, P, E) and may be accessed using a Central I/O (CIO) routine. • Interrupt Processing All hardware interrupts are handled by the interrupt subsystem in the Operating System. Vectored addresses contained in RAM memory point to subroutines in ROM to handle each type of interrupt. • Initialization There are two levels of initialization provided by the system, Power-Up and Reset. Power-Up initialization is performed each time the system power is turned on, and Reset initialization is performed each time the Reset key is pressed. Whenever the system power is turned on, the Operating System examines and notes the configuration of the unit. The Operating System performs the following actions at Power-Up: Determines the highest available RAM address Clears all RAM to zeroes Establishes all RAM interrupt vectors Initializes the ROM Cartridges Sets-up the video screen (2^ x i4-0 text mode) Boots the cassette if desired Checks ROM Cartridge for disk boot instructions Boots the disk if desired and a disk drive is attached Transfers control to the ROM cartridge, and booted program ATARI Home Computers 1-15 Whenever the Reset key is pressed, the Operating System performs some, but not ail, of the functions performed at Power-Up. The Operating System performs the following actions after the Reset key is pressed: Clears the Operating System portion of RAM memory Re-establishes all RAM interrupt vectors Formats the Handler Address table Initializes the ROM Cartridges Sets-Up the video screen for 2* x *0 text mode Transfers control to the ROM Cartridge and booted program The remaining 2K of Operating System ROM is a floating point program which is not used by the other parts of the Operating System itself, but is available to non-resident programs such as BASIC, Calculator, PASCAL, etc. The following routines are among those found in the ROM program; ASCII to floating point and floating point to ASCII conversion Integer to floating point and floating point to integer conversion Floating point log, exponent, and ploynomial evaluation Floating point number clear, load, store and move POWER SUPPLY The ifOO and SOO Power Supply have identical circuitry, with a few exceptions (See Figures 1-9 and 1-11). The Console Power Supplies receive 9Vac (J20* and J206, i*00 and 800 respectively) from the external power adaptor (transformer) provides +5Vdc, and ■i-12Vdc, and -5Vdc for the Console. Both the ^00 and 800 Power Supplies have two power ON/OFF switches, S202 and S203 for the ^^00 Console, and S201 and S202 for the 800 Console. S202 and S201, respectively, are Power Interlock switches. The RF signal is generated in both the 400 and 800 Power Supplies from the MOD signal received from the motherboard. It is routed through the A203 RF Module to develop the RF output through J203. A peripheral connector jack, 3202 for the *00 Console and J204 for the 800 Console, provides the serial data-in /data-out port for the system. Devices are "daisy chained" together from this output port. Each peripheral device is identified by a unique address, enabling all devices to reside on one output port. Also contained on the 800 Power Supply board is the Monitor connector jack (3205). Present at 3205 are the composite video signals to drive a video monitor. The 800 Power Supply board also contains switches S204 thru S207. These switches are the System Reset, Option, Select, and Start, respectively. ATARI Home Computers 1-16 ROM CARTRIDGE The Atari ROM Program Cartridge contains two ROM chips designed to provide a specific program application (See Figure 1-16). The 6502 microprocessor reads the information contained within the ROM chips by addressing memory locations SOOO thru BFFF Hex. When the ROM Program Cartridges are inserted in the motherboard, they disable the RAM address locations 8000 thru BFFF, in SK increments. The left ROM Cartridge overlays memory locations AOOO to BFFF, and the right ROM Cartridge overlays locations 8000 to 9FFF. ACCESSORIES AC Power Adaptor The AC Power Adaptor plugs into a standard wall outlet to provide the 9Vac used by the Consoles. The other end of the power adaptor plugs into the power jack on either Console. TV Switch Box The TV Switch Box allows the Console to be connected to the 300 ohm RF antenna or 75 ohm cable inputs on a typical televison set. 'BASIC Program Cartridge The 'BASIC Program Cartridge (provided) is a standard feature for both Consoles and contains the ATARI BASIC Interpreter. ATARI Home Computers 1-17 i¥ I I S3Nn «33»ix 3iaavd -^ a,OiCBi> m UuJ 3C ■ " ' " - ^ - • ' Tsfun loaiNOD omoaanvo mod nvia^T ii CTHVOS VWH 5^ inooaoiA a < 11 oavoa HdD u ?T ^ Figure 1-8. ^^00 Motherboard Flow Diagfam ATARI Home Computers 1-18 i2 = S ^ 2^5 2- 3e_ 25 = X 3 oo (S< _ as H 3*5 Figure 1-9. t^OO Power Supply ATARI Home Computers 1-19 — " u I > < — I ^^ — — o •• ' Jis3N[T aaasitu j, 5 = ^ % 1SV3 3nv9 XMSra ] T 1]IV3 3WV0 un m ■UJlVNQnU S « U35O0S) awo« wvu >31iSAOt J- moi ivims li 95 (13)OOS> (i35«30S) ino OHOU :J1 t s ^ ATARI Home Computers 1-20 Figure I-IO. SOO Motherboard Flow Diagram 4 s« Ui2 atOtO. X ■ua ac ^_ >- niVQM <-J jia =5 S3 Bl "~* "^ — • ■"* ir: i < < UK V 3E s §1 <s ' 5^ S* s 2 > lU ^ ^ m s at is 4 .a S s „3S Uo J ^* sis a < c J , 1 1 c 5 St u ac at O il 2 & 1 =5 -» UK -» i u o u * xai a£ < ' as 2 « X ' o u * = S ■3*3 < H B - « f " ■ ^ h« ^ r4 ■^■-^ 1 a < 3 ' ■ s ' 9£ il o I z lue O — at i/1 o [JIU HI a: Sis s£ IIJ *i •^ r»o •* -^ r^ 5 <-:-: > < — s 3 • r '3 *< 0*- Figure 1-U. 800 Power Supply Flow Diagram ATARI Home Computers 1-21 ADDRESS DECORDER/ DEMULTIPLEXER FOR OUTPUT DEVICES PIA, POKEY. GTIA & D3XX-D6XX ADDRESSES - i * DATA BUFF DECODE in u < <" p o >.' O 2a- > OS < Ui r < < of < 1 X X X G < 03 (/> ui a < 1- < Q 1 O Z o u 1/1 ui [L. LL D < ' 2 a X* X a as a o ui 2 < <3 ili£ as a < SI- J' ' UI S < • Oa < 1 01 3 U. U. ttJ Of 1 1 s. 2? ' UJ 1 1 r ' ' cnivoavaiuon oi ATARI Home Computer Figure 1-12. SQO Personality Board 1-22 *> < O < 1 ' , V J i o 1 a ^^ lU ILl -Jtt. J. LL. si i^N X * ■ s 0^=1 ff* c H IC ^ (/» -J u OS < a. y ' i i 03 < 1 o i 1 • r r 1^ > a -» o OS o S 1 s z 1 1 i ^ ■^"^ 1 — » -J (Li (/I (/I i k n* O z Cli A a < < ^ r r* § N i .ft f _r r ^ " ' L ^ 1 ^ u X £^ q<3 J J i-> UJ a 1/ s < a. < OS (J oa< C 1 1 r r r i ^ ■ 1 s s s i s P V ' f ^ 3 (/I S; iT (J T S I> r (^1 UJ UJ O Q z 5 tu 1/1 > < g - J / "^— . tt Is « * C < ! s Z L 3S ^ u k i 1 J i k iH </i UJ tu o ^ z 1/1 ^ < u u N tf u U OS UJ < u a. c UJ g z 3 of u (J o » (/) -) X U s. 1 1 V li ' f- z o u U 1 : . 1 V ik cravoa^aHiow oi 1-23 Figure 1-13. CPU Board Flow Diagram o 3 < M < Figure 1-1^. 8K Dynamic RAM Flow Diagram ATARI Home Computers 1-2* > Qi UJ Hi -J 11. J. u. H (11 01 < lU '- © i u < -J t a. X u < B i Of u X a. am ^•^ D (fi 1/1 [U a a <A sv^ au i tf to K A C3£ ai ti. u. lOi (D i 3 < u s < z > — (mVOO^IBRLOW OJ. Figure 1-15. 16K Dynamic RAM Flow Diagram ATARI Home Computers 1-25 — On n «n D US (/) a a < J?^ z»j52 ^!^ Oiu -1 tf -1 Su. _1Z < lU J D OQ<li. I t 1 a < OJ o < u < OHvog^raHxow 01 Figure 1-16. Game Cartridge Flow Diagram ATARI Home Computers 1-26 3 < a 1/1 > l/t a ?* 3 § U lU 3 O Z < < 3 u a§ - - ••3 Figure 1-17. ATARI Home Computer System Block Diagram ATARI Home Computers 1-27 SECTION 2 Sa.KSCREEN AND SCHEMATICS The following pages contain representative silkscreens and schematics for the ATARI *00/800 Computer Consoles. Minor variations in design may be encountered depending upon the production date of the Console. These drawings provide all details required for an in-depth understanding of both the *00 and 800 Consoles- ATARI Home Computer 2-i THIS PACl. LITENTIONALLY LEFT BLANK ATARI Home Computer 2-2 o a < J110 < Man iM u ASS 4iU* -d}' i o J109 C^ <t^^ C^' ^^S ^ 3 3 S 5 3 S O O ma 05 Figure 2-1. ^00 Motherboard Silkscreen ATARI Home Computer 2-3 a Figure 2-2. *00 Motherboard Scehmatic Page 1 of 2 ATARI Home Computer 2-^ Figure 2-2. WO Motherboard Scehmatic Page 2 of 2 ATARI Home Computer 2-5 aozo {} J ?< Oi =s 1 s At -> ,1 + 1 ^ -4 \- 2Qn 3 S cc oOg lOOiiO Figure 2-3. ^^00 Power Supply Silkscreen ATARI Home Computer 2-6 I Msfb 3-^-* — < "• uo ti s§ lVUH4l«3ri «a>t o — 2 212112 £ ■~ 91 r Figure 2-^. ifOO Power Supply Schematic ATARI Home Computer 2-7 THIS PAGE INTENTIONALLY LEFT BLANK ATARI Home Computer 2-8 lar (? zoir cor CCS toir "U tJ-*- I SP? i'ihnhhi'"ii 1 1^ II 'ii*" II Ni'ii'ti' k'lj^ii'ii'ri 'ii' II 'ii'b'ji' It'll 'ii '■'.■' II 'ti'ii'ij^^ A' I.' ■,',.'. '..'■.'. A — Figure 2-5. 800 Motherboard Siikscreen ATARI Home Computer 2-9 jUSt^CZZZ] ^ i J "*^ Lt!^ .j.l!5lilk Figure 2-6. 800 Motherboard Schematic Page 1 of 2 ATARI Home Computer 2-iO 'V- * * * * ATARI Home Computer Figure 2-6, 800 Mother Board Schematic Page 2 of 2 2-11 D 10 01 5T51 E C 10 CO «0Z3 Figure 2-7. 800 Power Supply Silkscreen ATARI Home Computer 2-12 Zta ur- 1^^ ^^ s^ ^5 *S Figure 2-8. 300 Power Supply Schematic ATARI Home Computer 2-13 10^0 801^0 60^0 OM £o^y 20i7"I COirl OlfrO ^ 20^0 OfrO CM o i I I o 1 csj O < fO O O O < ^ ^ Figure 2-9. 800 Personality Board Silkscreen ATARI Home Computer 2-U ^i±. •«tZI03 .a_ MOM 10*V llt> 5 2H2 — ^•4«iJH-- ¥i S .3. 1HM te»* s •|3l=Hsi=l*l-t •f'i*ii't'"!1"t^5aaia|sja yjt> *«l»t03 ,J, HON lOfrff ^ • 9 = a a: < o 03 o _ UJ P 0. < W 1ST Hl-r> HI- 5^ s -ffr a = 2" <• M ••« M 4 VVV V V • s f"t«.|9li«i« -.l» -(ifcts i 1 *1. ^Ifilxl 31 aixislais *! TT"TT T Figure 2-10. 300 Personality Board Schematic o « a ni w ATARI Home Computer 2-15 CIEU, I0£1 ~oi?a LO lOSV 90£U 1^ CPU ATARI Home Computer Figure 2- U. CPU Board Siikscreen 2-16 TT- I TTTTr "x, jL LT_iiT ^ ^J^ ATARI Home Computer 2-17 Figure 2-12. CPU Board Schematic CO 90fiZ ^8 -0 nt CM o X iO'SO O 1*1 lb ^ " iOSZ lOSZ 90SZ u la < SI S3 dZ:) sosz ^ OISZ - nsz • « zrsz Figure 2-13. 8K RAM Board Silkscreen ATARI Home Computer 2-lS < tr GO - umM _- !>= If :0 .|i<&ui.i,i^(,).ry a ,IM 'a!^ S ?5J_13J_Sf3li l^«|!|y|.|'-l!|sl-| .-r rOt-r— — — 5 ^* *? • i-1^ 5> U Os w 9 *r-r •% »^ I— _t >' ■rt-iaiJ-l.i-i-l,!-! 2 ■ Is! = 8 S S3 S Ha Sub = |3! Figure 2-U. 8K RAM Board Schematic ATARI Home Computer 2-19 go9Z 90SZ lO^Z 809Z 6092 >I9|. eu c^ lO S w w g « « ^ o o ]0 Oi 1093 O N to o lOi 6190 0I9Z o in CM O lO ts) 319 2 Figure 2-15. I6K RAM Board SUkscreen ATARI Home Computer 2-20 1^-> Figure 2-16. 16K RAM Board Schematic ATARI Home Computer 2-21 SECTION 3 TROUBLESHOOTING AND TESTING OVERVIEW This section describes the procedures to maintain, troubleshoot, and test the ATARI *00/800 Computer Consoles. The section is divided into two major categories: 1. TESTS 2. TROUBLESHOOTING TESTS The following discussions pertain to the troubleshooting procedures required to checkout the ATARI &00/800 Home Computer Consoles. Equipment Needed You ATARI ■equire six basic pieces of equipment in order to analyze the failures of the ' i^OO/800 Home Computer Console. These items include: 15MHz oscilloscope Stand Alone Test Cartridge (SALT II) Peripheral Port Test Connector Hand Controller Jack Test Connector Television Set (properly adjusted) Small Tool Kit ATARI Home Computer 3-1 Testing With And Without The SALT II Cartridge All tests are reviewed in this section. Procedures for the use of the tests are detailed in Section 5, *00 Diagnostic Flowchart, and Section 7, 800 Diagnostic Flowchart. OVERVIEW OF TESTS A variety of test routines assist you in identifying probable sources of problems within the computer console. Power-Up Test This test prepares the Console for the remainder of the tests. Should the Console fail this test, no other test results can be considered valid. • Format: Connect the power adaptor to the Computer and the Computer to the television set. Make sure there is not a cartridge in the console —turn the POWER switch ON. The words ATARI COMPUTER - MEMO PAD should appear on the screen in the upper left corner. Keyboard Test This tesx verifies that all keys of the keyboard are properly functioning. This test -Iso verifies that the POKEY chip's keyboard functions are operating properly. If one key faUs, then the problem is Ukely the keyboard. If more than one key fails, you must perform further tests. (These tests are discussed later in this section.) • Format: Depress each key of the keyboard. As you press each key, watch the screen to verify if the computer is echoing the key. Be certain to use the CTRL key with other keys. This checks special graphics functions not tested elsewhere (See Figure 3-1). RAM and ROM Test This test verifies that the CPU, RAM, and ROM chips are ail properly functioning. • Format: Due to the possible complexity of this test, it has been broken into four subsections. I. Turn the POWER off, insert the SALT II cartridge (for the 800, use the left cartridge slot), and turn the POWER on. The SALT Header should appear on the television screen (See Figure 3-2). This verifies that the CPU, Operating System (OS) ROMS, and the lower RAM are functioning. ATARI Home Computer 3-2 DO THIS PUSH PUSH SEE THIS PUSH PUSH SIMULTANEOUSLY PUSH PUSH SIMULTANEOUSLY Figure 3-1, Special Graphics Test ATARI Home Computer 3-3 ATARI 400/800 STAND ALONE SYSTEM TEST REV 2 04 (Type ? (C) 1981 FOR HELP) RAM:40K TIA NTSC ROM: MATH NTSA:NTSA Figure 3-2. SALT Header i^. If a green/yellow colored screen is returned, this indicates a probable OS ROM malfunction. Swap-out the ROM set with a known good set (make certain to test after each ROM is replaced), this allows you to pinpoint the defective ROM. If the words, SYSTEM FAILURE appear on the television screen, this indicates that the lower RAM is not functioning. When this happens and a *00 Computer is under test, turn the POWER off, swap-out the RAM board with a known good one and turn the Power on. If the SALT Header is returned to the screen, this indicates a probable malfunction in the RAM board which was removed. Refer to the DIAGNOSTIC FLOWCHARTS, Section 5 and 7 for troubleshooting procedures. If the 800 Computer is under test, turn the POWER off and swap-out the front RAM Card with a know good one. Place the suspected defective RAM CARD into the number 2 RAM slot (the third slot behind the OS), and turn the POWER back on. This lets the SALT II cartridge troubleshoot the suspected RAM CARD later in the DIAGNOSTIC FLOWCHARTS. If RAM and ROM boards have been swapped and the condition continues to persist, swap the CPU board with a known good board to isolate the problems. ATARI Home Computer 3-4 * • * NOTE * * » Once you have isoJated the problem to either the RAM, ROM, or CPU boards, clean the board edge connectors and retest the boards. The SALT 11 cartridge takes you through the next phase of tests. Use the SALT II cartridge to perform the following tests. SALT n Menu Figure 3-3 illustrates the SALT II menu of tests. The highlighted character in Figure 3-3 is red on the screen and is the command letter for each test. ANYV COLO Keyb IPORT mi mi 2 PRO HELP IDEO RBARS TEST IBOOT B IDT SPLAY LIGHT PEN ?HELP DUCTION TEST Figure 3-3. SALT II Menu ATARI Home Computer 3-5 Coior Bar Test This test verifies and allows for adjustment to the color circuitry. With SALT II properly in place, enter the command letter C and press RETURN, Figure 3-^ is a biack and white representation of what your television display screen should look like. REFERENCE BAR SAME COLOR Figure 3-*. Color Bar Test Screen A l5-color rainbow scale is displayed above the reference bar with a single color bar below. The color bars directly above and below the reference bar should be the same color (golden rod). If not, proper adjustment of R309 makes the color bars above and below the reference bar identical thus adjusting the coior frequency of the console to the proper setting. ATARI Home Computer 3-6 Proper operation of the unit is indicated by you being able to make this adjustment and by consistent color within the entire span of each bar on the screen. Minor glitches on the edges of the color bars are acceptable. Leave this test on for at least 60 seconds in order to catch any intermittent problems, such as a bar momentarily changing colors or blanking out. Any Video Test This test verifies the console's ability to generate a video (TV) display. This test also checks for pattern sensitivity of the rvNTIC chip. By entering the command letter A and pressing RETURN, this test is activated. Figure 3-5 illustrates the screen display for the Any Video Test. NOTE: Figure 3-5 is a black and white representation of a colored screen. The screen should have a black background with eight vertical bars. Half of the vertical bars should be narrow, and the other half, much wider. A horizontal bar should appear across the top of the screen. From the left to right, the shade of color on the horizontal bar should change. On the right of the bar, two Vs should be displayed, right side up; one in normal video and the other in inverse video. Figure 3-5. Any Video Test Screen ATARI Home Computer 3-7 Gray Bar Test This test verifies that the CTIA (GTIA) is generating the three LUM iines. By pressing the command letter G and then RETURN, this test activates. Figure 3-6 iiiustrates the screen display of the Gray Bar Test. The screen is divided into eight equal sized horizontal bars. The bar at the top of the screen should be black and subsequent bars should progress to white at bar eight. The bars should lighten in even shades. The screen should be steady and unchanging. These lines may have minor glitches at their edges. A thin white line should always appear just over the top (black) bar. No color should appear anywhere on the screen. The areas above the top (black) bar and below the bottom (white) bar are of no importance to this test. This test should be left on for at least 60 seconds to ensure that there is no "flashing" of color or shifting of the gray bars. Figure 3-6. Gray Bar Test Screen ATARI Home Computer 3-8 Keyboard Test This test verifies the Console's ability to accurately accept operator input from the keyboard. By pressing the command letter K and RETURN, this test is activated. You are to press each of the keys EXCEPT, the SPACE BAR, CNTL and both SHIFT keys. Each letter pressed is returned to the display screen. Once this portion of the test is completed, hold down the CNTL key and press the lette r A. The letters CTRL are returned to the screen. Now, hold down the left SHIFT key and press A. The word SHIFT is re turne d to the screen. By holding down the right SHIFT key and pressing A, the word SHIFT is again returned to the display screen. Finally, press the SPACE BAR and then, RETURN. The words KEYBOARD PASS or KEYBOARD FAIL appear on the screen below the keyboard test. If the SALT II cartridge detects any key failures during the test, the defective keys appear on the screen in the color red. Switch Test This test verifies the proper operation of the four Console Switches (START, SELECT, OPTION, and SYSTEM RESET). By pressing the command letter S and pressing RETURN, this test is activated. Press the console switches in the following order: 1) START; 2) SELECT: 3) OPTION; and ^f) SYSTEM RESET. Upon pressing SYSTEM RESET, either PASS or FAIL is returned to the screen. Tone Test This test verifies the ability of the POKEY to generate four sound registers through its sound generation circuits. Press the command letter T and RETURN. A prompt (question) is returned to the screen asking you which register you want to test. You must press the key with the number of the register you want to test (1, 2, 3, or *) and then press RETURN- The test generates eight tones in descending order. The first three tones are very nigh and may be inaudible to some people. Each tone begins at maximum volume and fades to minimum volume. You must enter the command letter before each register test. Make certain to test all four sound registers. NOTE: The television volume control may have to be turned up in order for you to hear the first three tones. ATARI Home Computer 3-9 Display Options This function, which is not a test, displays a diagnostic matrix when used in conjunction with either the RAM TEST or the PORT TEST. It allows you to identify which ROM chip has failed when used with the VERIFY ROM TEST. By pressing command letter D and RETURN you access this function. The screen returns the prompt to enter a test format, To use the PASS/FAIL indicator, enter the command letter P and press RETURN. To display the ERROR TABLE, enter the command letter E and press RETURN. For the following PORT, VERIFY ROM, and RAM TESTs, press the command letter E and RETURN. The screen prompts you to enter the command letter S for a single test, or C for continuous testing. You are now ready for the three tests. To terminate any of the following three tests, press the SPACE BAR. NOTE; The RAM test completes its current test before stopping. Port Test This test verifies the ability of the computer system to communicate through the controller jacks and the peripheral I/O port. The command letter P and RETURN activates this test. Make certain that the Peripheral Jumpers are in place, and press RETURN again. Figure 3-7 illustrates the Port Test Matrix Display. This figure is a biack and white representation of a color television screen. The zeros should be a blue tint. 0000 0000 0000 0000 210 000 000 0000 8888 0000 0000 0000 0000 0000 PORT TEST ERROR COUNTER TEST COUNTER Figure 3-7. Port Test Screen ATARI Home Computer 3-10 The four digit number in the lower-right corner of the dispiay screen shows the number of tests completed. In addition, the four digit number above it in red is an error counter which indicates the number of times the test has failed. If a failure occurs, a Red 1 is displayed in the matrix, this shows you the location of the errored condition. Table 3-1, Port Test Legend should be used to determine the cause of the failure condition. (Please note, a blinking 1 at location A 5 does not indicate a failure.) A passing condition for all test is indicated by a in that location (i.e., CO or D*). If the failed test passes on the next pass, the 1 is replaced by a 0. The error counter in the lower-right corner of the screen increments by one for each error . Verify ROM Test This test checks the Console's ROMs by performing checksum tests on them. By entering the command letter V and pressing RETURN you activate this test. The screen displays a checksum for each ROM and the value returned by the MATH PACK together with a PASS or FAIL indicator for each. • Upon completion of the test, the screen displays VERIFY ROM and either PASS or FAIL for the entire test. This test can be used to pinpoint which ROM is failing. If you suspect a ROM is intermittently failing; run this test for 15 or 20 minutes. RAM Test This automatically uses six different tests to verify the operation of the RAM boards- Enter the command letter R and press RETURN to begin this test. A prompt is returned to the screen asking how many 8K blocks of memory to check (maximum of five). Type the number of memory blocks in the unit and press RETURN. (Remember that, 1 equals each 8K RAM card and 2 equals each 16K RAM.) The computer displays the amount of RAM it is testing. If the amount is not what you entered, one of two conditions may exist: 1) the unit does not contain tne amount of memory you thought it did; or, 2) the unit has defective RAM card(s). Figure 3-8 Ulustrates a defective RAM test system response screen. The four digit number in white at the bottom right of the screen indicates the number of tests completed. A red four digit number directly above this is used to count the number of failures. ATARI Home Computer 3-1 1 Table 3-1 Port Test Legend 9^ la !.-: « -3 S s h S.-s 3^« S -« -t P ft ~ c, /I /- Z 35 3£ <auQ»CBioa: ATARI Home Computer 3-12 As was the case with the PORT Test, failures appear as Red Is in this display. If the pattern is in a state of constant change, one of the RAM boards probably has a set of defective 7*LS158 chips. If you replace the chips make certain that the new chips have the same manufacturer and the same date code. This ensures compatibility. To determine which board(s) is(are} defective, perform the following three steps: 1) Turn off the power, 2) Remove one of the boards. 3) Start the test from Display Options, page 3-10. If the pattern is stable, look at line B, Columns * thru 7 to determine which board is defective, (See Table 3-2). D E 4 0100 0001 0000 0000 RAM 0000 1000 0000 TEST TESTING 40 K 0004- 0004 ERROR COUNTER TEST COUNTER Figure 3-S, RAM Test Screen ATARI Home Computer 3-13 Table 3-2 Defective RAM Boards Defect Indicator Description Bifr ist SK Block 2nd 8K Block B5; or B4 and B5 B6;or B* and B6 B5 and B6; or Ba, B5 and B6 B7; or B4 and B7 3rd 8K Block *th 8K Block 5th 8K Block Compare rows D and E, if there is a difference between any one column use Table 3-3 to identify specific defective chips. If more than one column is different replace the 7£fL52^4 chip and retest. ATARI Home Computer 3-Iif Table 3-3 Defective RAM Identifier Difference Column Description 8K I6K DO Z512 Z512 Dl Z5U Z5U D2 Z510 Z510 D3 ZJ08 Z509 D* Z509 Z5(j4 05 Z507 Z507 06 Z505 Z506 D7 Z506 ZJ05 M Test P?i?-,^*^^ ^*^^^®5 ^^® proper operation of the Video Buffer Chip (400-Aill and 800- A103}, To perform this test, turn off the Console POWER, remove the SALT II cartridee and insert the BASIC cartridge. Turn the POWER on and perform the following three entries; ® ATARI Home Computer 3-15 1) Type: NEW and press RETURN. 2) Type: 10?"M-; :GOTO 10 and press RETURN. 3) Type: RUN and press RETURN- The system starts printing Ms, character after character, line after line- If any are blurred and/or nin together, the Video Buffer Chip or another of the discrete components in the video summing circuitry on the mainboard is probably defective. To stop this test, press BREAK or SYSTEM RESET, STAR RMDEr'^^ Test If the Console has effectively passed all previous tests and performs this game without any visible problems, it is almost certainly operating properly. Turn POWER off, remove the BASIC cartridge, insert the STAR RAIDER^^ cartridge, and turn the POWER on. Now, go through the game's various screens and functions (play the game). Shake Test Grasp the unit firmly with both hands and shai<e it vigorously for approximately 10 to 20 seconds. DO NOT HIT or STRIKE the unit against the bench or other hard object without having your fingers between the unit and the surface being struck. Perform the MEMO PAD test to make certain that none of the connections, boards, and/or components have become unseated, and that the unit is properly operational. Burn in After the unit has successfully passed all the previous procedures and is operating correctly, it is ready for burnin Burnin consists of operating the system continuouisly for a long period of time (recommended S hours). Use one of the following three methods. i) Insert the SALT II cartridge and run it with continuous RAM or PORT test. 2) Insert Star Raider or another game cartridge and run it. 3) Perform the ^tOO/SOO Console Test (810 Disk Drive required). ATARI Home Computer 3-16 At the end of the BURN-IN period, check the unit again for any malfunctions, using SALT II Test checks. Once the unit has passed all the final checkout procedures, it is ready to be returned to the customer. DESCRIPTION OF THE OTHER FUNCTIONS FOLLOWS; Production Test Command letter "Z". This function allows you to run through the series of test semi- automatically by pressing the space bar. It will ask you the serial number of the unit and print it out on a printer with the word PASS or FAIL. Soot B This function is not used at this time. Examine Command letter "E". This allows you to test a specified RAM location (address). Adjust Command letter "3". This is used to debug audio and serial port control lines (Motor ?.. £°"^^and) on the system console. A fixed frequency audio signal is produced while PIA ports are exercised. SUMMARY This section has taken you step-by-step through aU the tests and general troubleshooting steps required for evaluation of a suspect defective *00/800 console Now read through the section, DISASSEMBLY and ASSEMBLY, before going on to Section 5, Diagnostic Flowcharts, and Section 7, 800 Diagnostic Flowchart. ATARI Home Computer 3-17 SECTION » DISSASSEMBLLY/AS5EMBLY MAINTENANCE ATARI WO HOME COMPUTER CONSOLE - DISASSEMBLY The following describes the procedures required to disassemble the *00 Computer Console. Read the following NOTES first, then proceed. • • • NOTE • ♦ ♦ L Be very careful about mixing screws. Plastic and aluminum parts can be easily stripped or damaged by puncture If the wrong size screw is used. Z. Excessive torque on screws can strip the plastic and aluminum parts. o Plastic - 6-inrh pounds torque maximum. o Aluminum - 10-inch pounds torque maximum. 3. Protect the plastic surfaces of the console by working on a soft surface (a grounding pad works very well) when the Console is turned over, bottom up. *. Use ALL static control precautions when handling any printed circuit board. KEYBOARD AND POWER SUPPLY ACCESS To remove the top cover, perform the steps in the exact order given. • Turn the unit side down. • Remove four screws from the bottom cover (See Figure ^f-l). ATARI Home Computer i^-1 BOTTOM COVER Figure *-l. ATARI £*00 Console, Bottom Cover Screw Location Turn unit upright. Unhook top cover from keyboard (see Figure f-2). Open cartridge door. Lift top cover off. ATARI Home Computer ^-2 TOP coven Figure *-2. ATARI WO Console Top Cover Removal KEYBOARD REMOVAL To remove the keyboard, perform the following steps in the exact order given. Use Figure ^3 as a reference for the following two steps, • Remove single Iceyboard screw, • Lift left end of keyboard and disconnect keyboard ribbon cable. ATARI Home Computer ^^-3 Figure *-3, ATARI *00 Console, Keyboard Removal POWER SUPPLY REMOVAL To remove the power supply, perform the following steps in the exact order given. Use Figure *-4 as a reference for the following four steps. • Disconnect RF cable from power supply. • Remove two screws from power supply. • Gently pull power supply away from casting l/£f inch and lift out the interlock switch plunger. • Lift the power supply straight-up off the motherboard connector pins. ATARI Home Computer if_4 INTERU3CX PLUNGER X INTERLOCX / SWITCH POWEJ? SUPPLY MOTHEH aOAPO CONNECTOR RF CASLS Figure *-*. ATARI WQ Console, Power Supply Removal ATARI Home Computer £^-5 CPU, RAM, AND MOTHERBOARD ACCESS To remove the module assembly, perform the steps in the exact order given. Use Figure ^5 as a reference for the following two steps. Disconnect and remove speaker assembly. Lift module assembly out of the bottom cover. CPU AND RAM REMOVAL To remove the CPU and RAM printed circuit boards, perform the steps in the exact order given. Use Figure *-5 as a reference for the following six steps. Close and latch the cartridge door. Set the module on its back- Remove the eight screws from the bottom shield and lift off the shield. Lift the motherboard assembly out of the aluminum casting. Carefully unplug the CPU and/or RAM boards. Unhook and remove the plastic cartridge guide. ATARI Home Computer if-6 CPU aOARO RAM BOABD suioe SPEAKER ASSCMSUr AUIMINUM CASHNG MOTHER aOARO SCrrOM SHIELD Figure ^-5. ATARI f^00 Console, Module Assembly This concludes the disassembly of the WO computer console. ATARI Home Computer *-7 ATARI 800 HOME COMPUTER CONSOLE - DISASSEMBLY The following describes the procedures required to disassemble the ATARI SOO Home Computer console. Read the NOTES on pages ^t-l thru ^- 3 first, and then proceed. ACCESS TO RAM BOARDS AND ROM BOARD To gain access to the RAM and ROM boards, perform the steps in the exact order given. Remove the cartridge door assembly. Use Figure '^-6 as a reference for the following eight steps. • Turn the system power switch to the OFF position. • Open the cartridge door. • Turn the cartridge door clamps towards the outside of the Console. • Lift the cartridge door assembly 1/* inch, pull it towards you, and lift it off. Remove the RAM and ROM modules. • Lift out the RAM module<s), • Lift out the ROM module. • Lift out any cartridge<s). Turn cartridge door clamps to original position. • ATARI Home Computer i^-8 CARTRIDGE DOOR ASSEMBLY Figure t^-6. ATARI 800 Console, Cartridge Door Assembly Removal ACCESS TO POWER SUPPLY AND KEYBOARD ASSEMBLY To gain access to the power supply and keyboard assembly, perform the following steps in the exact order given. REMOVE TOP COVER Use Figure *-7 as reference for the following three steps. • Turn unit upside down. • Remove five screws from the bottom cover. • Tilt the back of the bottom cover up and towards you to remove it. ATARI Home Computer ^^-9 BOTTOM COVQI Figure 4-7. ATARI 800 Console, Bottom Cover Removal REMOVE THE PCB MODULE Use Figure *-8 as a reference for the following seven steps. Remove two screws from the aluminum casting flange. Remove the single screw from the power supply board (lower left corner). Disconnect speaker cable, remove speaker and set it aside. Turn the unit over. Carefully pull the back of the console top cover assembly to 90° separating it from the PCB module. ATARI Home Computer if-10 Reach over the top cover and unplug the keyboard's ribbon cable. Set the top cover assembly aside. Lift the power supply board straight up. Remove plastic cartridge guide by unhooking the latches from the bottom side of the motherbcard- MO0UU£ ASSCMBLT KCYBOAin} RiaaoNCAaL£ SPCAKER HAHNESS Figure ^^-3. ATARI 800 Console, Module Assembly Removal REMOVE THE POWER SUPPLY Use Figure *-9 as a reference for the following five steps. • Unplug the RF cable from the power supply board. • Unplug the power supply harness, • Remove three screws from power supply board. ATARI Home Computer *-U RF CABLE POWER SUPPLY MOTHER BOARD CONNECTOR WIRE HARNESS Figure *-9. ATARI 800 Console, Power Supply Removal ACCESS TO CPU PRINTED CIRCUIT BOARD Use Figure ^-10 as reference for the following four steps. • Turn the unit upside down, • Remove the nine screws from the lower shield, • Lift the motherboard and lower shield out of the aluminum casting. • Remove the CPU PCB. ATARI Home Computer if-12 ALUMINUM CASniM Figure *-lO. ATARI 800 Console, CPU Printed Circuit Board Removal ACCESS TO MOTHERBOARD Use Figure ^11 as reference for the following three steps. • Carefully slide the tip of a screwdriver underneath the motherboard next to the nylon clip. Gently raise the handle of the screwdriver, prying off the nylon clip. Repeat this operation for the remaining three nylon clips. » » * CAUTION • » ♦ Be care&l not to bend any of the pins on the Motherboard Connector. Do NOT allow the tip of the screwdriver to damage traces. ATARI Home Computer i*'{3 Lift the motherboard off the lower shield. Remove the plastic cartridge guide by unhooking the four latches from the bottom side of the motherboard. cAimiooe suioe aOTTQM SHIGLO Figure ^-11. ATARI SOO Console, Motherboard Removal KEYBOARD REMOVAL Use Figure *-l2 as reference for the three steps, to remove the keyboard from its case. • Turn the top cover upside down. • Remove four screws from the four corners of the keyboard. • Lift the keyboard out of the top cover. This concludes the disassembly of the Atari 800 Home Computer console. ATARI Home Computer i^-U KEYBOARO TOFCOVCR Figure *• 12. ATARI 800 Console, Keyboard Removal ATARI WO HOME COMPUTER CONSOLE ASSSEMBLY The following outlines the steps required to reassemble the Atari t*-OQ Home Computer console and it's related printed circuit boards. MODULE ASSEMBLY REASSEMBLY Refer to Figure i^-5 as reference for the following five steps. • Snap the cartridge guide into the motherboard (it only goes in one way). • Insert RAM and CPU printed circuit boards into the motherboard with the component side of the PCBs facing away from you. Before reassembling the PCBs, make certain that they have been cleaned and lubricated. (Refer to pages *-21 and *-22 for instructions.) ' • Set aluminum casting upside down, invert the motherboard and gently lower it into the casting. Atari Home Computer ^^-15 • * • NOTE * * • The CPU PCB must fit into the guides in the aluminum casting. • Install lower shield and secure it with eight screws. • Install the module assembly in the bottom cover. KEYBOARD INSTALLATION Refer to Figure 1-3 as a reference for the following three steps- • Plug the speaker cable into the motherboard (no Polarity) and set the speaker into the bottom cover. • Plug the keyboard ribbon cable into the connector on the motherboard. • Gently lower the keyboard over the Power-ON LED and guide posts on the aluminum casting. POWER SUPPLY INSTALLATION Use Figure ^^-^ as reference for the following five steps. • Align the power supply over the motherboard connector pins and bottom cover guide posts and gently press it down. • Install the interlock switch plunger into the aluminum casting. Make certain that the lower end of the plunger is positioned over the interlock switch and the plunger shaft rides in its notch in the power supply heat sink. • Insert and tighten the two power supply mounting screws. * • * CAUTION • * * Be sure that the RF cable is not trapped under the module assembly. • Route the RF cable through its slot in the power supply board and plug it into the power supply jack. • Insert and tighten the single keyboard mounting screw. Atari Home Computer ^-lS TOP COVER INSTALLATION Open the cartridge door. Slide the top cover down over the open cartridge door and the power-ON LED (Refer to Figure '^-2), Guide the top cover locator pins into the keyboard holes and snap the top cover hood under the keyboard- Close the cartridge door and set the console on its face. Align the top and bottom covers and Insert the four screws into the bottom cover and tighten (Refer to Figure *-l). ATARI 800 HOME COMPUTER CONSOLE ASSEMBLY The following outlines the steps required to reassemble the Atari SOO Home Computer Console and its related printed circuit boards. KEYBOARD INSTALLATION Refer to Figure '^-12 as reference for the following two steps. • Set the top cover upside down with the keyboard in it, • Insert and tighten the four mounting screws. » * * NOTE * » • Check the spacebar and keys to make sure that they are not binding before proceeding. MOTHERBOARD INSTALLATION Refer to Figure '^-ll as reference for the following two steps, • Snap the plastic cartridge guide into the top side of the motherboard. • With the motherboard right side up, snap on the four nylon clips of the lower shield. Make certain all four clips are firmly seated. Atari Home Computer i^-17 CPU PCB INSTALLATION Refer to Figure ^-10 as reference for the following five steps. • Plug in CPU PCB, Make certain the component side of the board faces away from the plastic cartridge guide and is firmly seated. • Turn the aluminum casting over. • Turn the motherboard upside down and set the motherhoard and lower shield into the aluminum casting. • • * CAUTION * • ♦ Make certain that the CPU PCB sets in its slot in the aluminum casting. • Insert and secure the nine screws in the lower shield. • Set the console on its feet. POWER SUPPLY INSTALLATION Refer to Figure ^9 as reference for the following six steps. • Carefully align the power supply connector with the motherboard pins. • Set the power supply down over the guide pins on the aluminum casting and gently press down. • Attach strip connector between power supply and motherboard. • Insert and tighten the three screws of the power supply board. • Recommend the power supply harness. * * * CAUTION • » » Plug the power supply harness cable from the motherboard to the power supply pins with the orange or purple wire towards the aluminum casting. • Plug the RF cable, the short end, into the power supply jack. Atari Home Computer £^-18 MODULE ASSEMBLY INSTALLATION INTO TOP COVER Refer to Figure ^^-8 as reference for the following six steps. • Set the top cover upside down, • Invert the module assembly and lower it into the top cover. Turn the cartridge door latches toward the inside in order to clear the top cover. • * * CAUTION * * • Make certain that the RF cable is not trapped between the power supply board and the top cover standoff (upper left screw hoie). • Lift the motherboard one-inch out of the top cover and plug in the keyboard hamess- • Insert and tighten two screws into the front holes of- the aluminum casting and into the top cover. • Set the speaker into its receptacle foam side down. . Connect the speaker cable to the jack (no polarity). • BOTTOM COVER INSTALLATION Refer to Figure ^7 as reference for the following four steps. Align the bottom cover with the four-hand-controller ports. Seat bottom cover firmly, all the way around. Make certain the RF cable exists through its hole and is not trapped between the covers. Insert and tighten the five bottom cover screws- Set the console right side up. Atari Home Computer i^-lS RAM AND ROM MODULE INSTALLATION Refer to Figure *-6 as reference for the foliowing two steps. • Insert the ROM Module in the slot closest to the keyboard. • Insert a maximum of three RAM modules in the remaining slots. CARTRIDGE DOOR ASSEMBLY Refer to Figure '^7 as reference for the following two steps. • Set the cartridge door assembly on the top cover and slide it to the rear of the cover. This action engages the tab of the door into the aluminum casting. • Loci< the cartridge door assembly down with the two clamps next to the program cartridge slots. PCS CONTACT CLEANING AND LUBRICATION The following instructions explain the procedures required to properly clean and lubricate the PCB contacts of the CPU, RAM and ROM boards once they have been removed from the motherboard. Tools Required ZEP Safety Solvent or Isopropyl Alcohol Dust-Free Cloth Acid Brush Board Cleaning Brush Libriplate (DS-ES Lubricant) Procedures 1. Inspect the PCB contact for flux, dirt, foreign material, and deeply serated contact fingers. 2. Moisten the dust-free cloth with solvent and clean the finger contacts. Make sure both sides of the contacts are clean and free of residual lubricant and contamination. Atari Home Computer if-20 * ♦ * NOTE ♦ * * Avoid touching the contact after cleaning. 3. If corrosion or residue remain on the contacts it is necessary to clean the contacts further using the board cleaning brush. Use the following procedures- • Moisten the board cleaning brush with solvent and firmly brush the contacts. Four to six strokes is enough. Be careful and do not touch any other part of the board. • Perform step 2 again. *. Dip the acid brush into the lubricant. 5. Apply an even coating of lubricant to the contact fingers on both sides of the PCB. The coating of lubricant should be thick enough to protect the contact fingers from corrosion- Do not spread the lubricant to areas other than the contact fingers. VISUAL INSPECTION The following instructions explain specific areas to check on the Consoles for damage or abuse. 1. Inspect the controller jacks and peripheral jacks for broken and/or bent pins. 2. Check the RF cable for cracks in the insulation, bare, or pinched areas. 3. With the console power ON and MEMO PAD on the screen, open the cartridge door to check the interlock switch. Usinj^ a small blade screwdriver, press the plunger down. Release the plunger and see that it Is returns to its open position. In its open position the console is powered- down. ^. Inspect the cartridge slot for foreign objects or damage. 5. Inspect the power jack for bent and/or damaged pins. If any of the above damage is found, repair the defective area. Use the disassembly and assembly instructions at the beginning of this section. Atari Home Computer i^-21 SECTION 5 WO DIAGNOSTIC FLOWCHART The Diagnostic Flowchart is intended to be easy to use and the primary aid when troubleshooting the ATARI WO Computer Console. Follow the prompts in the order presented. When a question is asked, follow the line from that box which best applies to the unit's situation. The flowchart leaves little to chance, it tells you when to perform a specific test and when to replace components. Swap Out Procedure At many places in the diagnostic flowchart, a box tells you to "swap-out" a chip or a number of chips in a particular order. The "swap-out" instruction means that you should replace the indicated components (one at a time) with a known good component of the same type. The 400 should then be tested with the new, known-good component in place to see whether the "swap-out" solved the problem being checked. If the swap- out did not fix the problem, the known-good component should be removed, and the original component reinserted. In this way, you avoid needlessly replacing good components. CAUTION: Extreme care shouid be taken when handling the integrated circuit, chips. They are all v«3r sensitive to static electricity and can easily be damaged by careless handling. Always keep the chips in their plastic carrier tubes or on conductive foam when not handling them. Make certain you are well grounded when handling the chips. Atari strongly recommends that you wear a conductive grounding band (which ties from yow arm to ground) when handling the chips. Thediijw are also susceptible to damage from stress when being removed from or inserted into the sockets. Always use a chip-puUer when removing the chips. Do not pry the chip out with a screwdriver or any other tool. Failure to follow the above guidlines results in unusally high chip failure rates and extra expense. ATARI Home Computer 5-1 400 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS Remove any Carcrldpe and Power-up Console Is a clear MEMO PAD YES teat special graphics mode of keyboard using Figure 3-1 YES NO Co to START, next pave Pass Go to POWER-UP, PART II, Page 5-8 NO . I N'oce failures t co be used lacer with keyboard cesc ATARI Home Computer 5-2 400 FOWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS SNOWY SCREEN Is tha scre«n snowy YES NO Go to Slack/ Gray Screen, Page 5-4 Check, adjust, or replace AC power aciaptor, channel select switch and TV switch box Is a clear MEMO PAD on the screen NO Does Power Supply Board. J201. Pins 3. 6, and 7, have +5v YES' NO I Is there a good ground connection at Pin 1 of RF Module Repair YES, Is a clear MEMO PAD on the screen NO YES Go to POWER-UP, PART II. Pa^e 5-8 YES Is the RF Module mistuned or defective NO Go to Black/ Gray Screen. Page 5-4 YES I Go to POWER-UP: PART II, Page 5-8 MO Check . repair . or replace the following: CR206-CR209. replace IN4001 type diodes with IN5391 (C017988) Does voltage reg- ulator (A202) have +5v Check C208. C209, R203, and S202 - replace if defective Is a clear MEMO PAD on the screen NO YES ATARI Home Computer 5-3 400 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS BLACK/GREY SCREEN Is the screen black or gray lYES NO Check Power Supply Board for: Is there -5v on J201 Pin 18 iGo to GREEN /YELLO I SCREEN, Page 5-^ NO YES Check, repair, or replace the following: CR206 - CR209 - replace 1N400I type diodes with 1N5391 (C017988) CR201 - Ca203, and C2ai, C202. and C210 Is there >I2v an J201. Pin 2 NOTE 1 See Table 5-1, start at the top of it and trace back until clock signal appears, indicating which component has failed. / / NO YES Check . repair , or replace the following; Voltage Regulator (A20I), CR204 and C203 - C205 Check the CPU Board for: '' Clock Circuit (see NOTE I) Chip Reset Voltages: NO Is there +5v on A302, Pin 36 and A303, Pin 30 Repair YES Replace CTIA/GTIA (A301) Is a clear MEMO PAD on- the screen YES Go to POWER-UF. PART II. Page 5-8 NO Go to C, next page ATARI Home Computer 5-4 400 POWER-UP CATASTROPHIC FAILURES AND BASIC OPSaATIONS 3LACK/GREY SCREEN { cont ) On the Mother- board Swap-out A103. Alll 2103 - ZX05. QIQ3, Q104. and XlOl Is a clear MEMO PAD on the screen NO Check and replace discrete components In video summing circuitry Is a clear MEMO PAD on the screen YES Go to POWER-UP, PART II, Page 5-8 YES Go to POWER-UP, PART II. Page S-a NO Go to GREEN/YE14.0W SCREEN. Page 5-6 ! ATARI Home Computer 5-5 400 POWE-?.-U? CATASTROPHIC FAILURES AiVD 3A5IC OPERATIONS GREEN /YELLOW dCREEN Is there a defective YES Repair RAM card in the Unit (check lowest RAM slot arst) YES 'S NO Swap-out ROMs F(A103), E(A104), and D(Aia5} Is a clear MEMO PAD on the screen Go to POWER-UP, PART II. Page 5-8 YES NO Swap-out the following A303. and Z303, and Z3a4 Is a clear MEMO PAD on the screen - Go to POWER-UP, PART II. Page 5-8 NO Go to SOUD BLUE SCREEN. Page 5-7 ATARI Home Computer 5-6 400 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS SOLID BLUE SCREEN Are the words - YES Go to POWER-UP, PART II. Page 5-8 MEMO PAD on the screen NO /"^ NO [DO) ■ Swap-out the POKEY (AlOl) chip Is the screen strictly BUck and Vbita NO YES Swap-out 0X07 and XIOl on Mocherbaord Is a clear MEMO PAD on the screen Call ATARI Tech Line j Specialist 1 _. YES Inside California (800) 672-1466 Outside California i Go to POWER-UP, PART II Pase 5-8 (800) 538-1535 I (800) 538-1536 ! . 1 ATARI Home Computer 5-7 400 POWER-UP. PART 11 <3tarO Turn power OFF, Insart SALT II Cartridge, and turn power ON RAM: Do«9 screen look like Figure 3-2 See NOTE 2 YES NO la there ^40 color or are the coiors off YES Go to COLOR BAR Teat, P»ge 5-9 NO Is the screen solid green, yeilow, or red YES Reeat SALT II Cartridg* and reteat NO Does screen look like Figure 3-1 Repeat POWER-UP^— *" PART I, Page 5-2 YES NOTE 2 could be 3K. 16K. 24K, 32K. oe 40K TIA: couid be NTSC or PAL ROM: could be - MATH:NTSA:NTSA MATH:NTSa:NTSB MATH:PALA:PALA ' MATH:PALS:PALB ERR: ia displayed for any bad ROM, verify error condition via VERIFY aCM Teat, Page 5- Go to COLOR BAR Teat. Page5-9l ATARI Home Computer 5-8 COLOR BARS Preaa C and RETURN Oo*a screen look like Figure 3-4 NO Can you adjust R309 to the proper color YES Adjust R3Q9 Does screen look like Figure 3-4 NO Go to COLOR BAR TROUBLESHOOTING, Page 5-lQ Does MENU appear NO i (Refer Figure 3-3) j @ YES YES NO YES Repeat POWER-UP, Page 5-2 Go to TIA, Page5-10 Go to COLOR BAR TROUBLESHOOTING . Page 5 -10 Go to TIA. Page 5-10 ATARI Home Computer 5-9 400 COLOR BAR TROUBLESHOOTING STAR Swap-out A301 and A302. on CPU Board Oo«9 screen look like Figure 3-4 NO Swap CPU Board Does screen look Uke Figure 3-1 NO Swap-out Alll, Q107 on Motherboard Does screen look like Figure 3-4 YES Go to TIA, Page 5-13 YES Trace color circuitry on CPU Board. Make cetain to check color delay circuit and R3Q9 YES Go to TIA. Page 5-13 NO Go Co next page ATARI Home Computer 5-10 400 COLOR BAR TROUBLESHOOTING (cont) Verify that each o£ tfaa foUowing levels and/or signal wave forms exist before procee<iing to the next step. Use SALT 11, COLOR BARS. locked into the continuous mode. Is there 3.58MH2 oscillation at R1S8 on Motherboard. Refer Figure YES Is there input signal to base of Q107 Refer Figure YES Is there output signal from collector on Q107 Refer Figure , YES NO Swap-out XlOl. Q103 and 0104 NO Trace circuit back to previous step NO Trace circuit back previous step to Is there signal at J107. Pin 1 Refer Figure NO Trace circuit back to previous step YES Go to next page ATARI Home Computer 5-U 400 COLOR BAR TROUBLESHOOTING (cont) Are the following present Refer Figure -•^v on Modulator Pin 5 Signal on Modulator Pin 4 Signal on Modulator Pin 2 YES Does screen look like Figure 3-6 NO NO Trace circuit back to previous step JSS. Go to TIA, Page 5- 18 Call ATARI Tech Une Specialist Inside California (800) 672-1466 Outside California (800) 538-1535 (800) 335-1536 ATARI Home Computer 5-12 TIA TEST CSTART^ YES Press I and RETURN Da«s NOT GTIA appear on screen Go to GRAY BAR | YES rest, Page5-14 NO Is there a color rainbow on the screen Go to GRAY BAR Test, Page 5-14 NO Replace GTIA (A301} on CPU Board ATARI Home Computer 5-13 400 GREY BAR YES YES YES Press G and RETURN Does screen look like Figxire 3-6 NO ^ Replace CTIA/GTIA (A301) Does screen look like Fiaure 3-6 NO Replace Alll Does screen look like Figure 3-6 Co to ANY VIDEO, Page 5-18 NO Go to 400 GREY BAR TRCUBLESHOOTING, Paste 5-15 ATARI Home Computer 5-iif 400 GREY BAR TROUBLESHOOTING Swap-out A301 and A302. on CPU Board YES Doas screvn look like FIgun 3-6 Go to ANY VIDEO, Page 5-18 YES NO Swap CPU Board Ooos 9cr««n look Uk« Figure 3-6 Trace color circuitry on CPU Board. Make cetain to check color delay circuit and R309 YES NO Swap-out Alll. Q107 on Motherboard Does screen look like Figure 3-6 Go to ANY VIDEO, Paye 5-18 NO Go to next page ATARI Home Computer 5-15 400 GREY BAR TROUBLESHOOTING (cont) Verify that each of the foUowing levels and/or signal wave foras exist before proceeding to the next step. Use SALT II. COLOR BARS, locked into the continuous mode. Is there 3.S8MHz oeciUation at R158 on 'Motherboard. Refer Figure ■iiamia NO Swap-out XlOl. Q103 and QI04 YES Is there input signal to base of Q107 Refer Figure NO Trace circuit back to previous step YES Is there output signal from coilectot on QIO? Refer Figure NO Trace circuit back to previous step YES Is there signal at J107, Pin 1 Refer Figure NO Trace circuit back to previous step YES Go to next page ATARI Home Computer 5-16 400 GREY BAR TROUBLESHOOTING (cont) Ar« tha foUowtng presant Glefer *5v on Modulator Pin S Signal on Modulator Pin 4 Signal on Modulator Pin 2 YES Ooaa scraan look Uka Figura 3-6 NO NO I Trace circuit back to " pravious step JCSS. Go to ANY VIDEO, Paga 5-18 Call ATARI Tech Line Specialist Inside California (800) 672-1466 Outside California (800) 538-153S (800) 538-1536 ATARI Home Computer 5-17 400 ANY VIDEO II Press A and RETURN Does scrsttn look like Figura 3-5 NO Replace ANTIC (A302) on CPU Board Does screen look like Figure 3-5 NO RepUce CTIA/GTIA (A301) Does screen look like Figure 3-5 NO JZS. YES XZ2. Go to KEYBOARD Test, Page 5-22! Go to 400 ANY VIDEO TROUBLESHOOTING. Page 5-19 ATARI Home Computer 5-18 400 ANY VIDEO TROUBLESHOOTING TAH: Swsp-^ut A301 and A302. oa CPU Boarti YES Ooma scre«n look Uka Figure 3-5 Go to KEYBOARD. Page 5-22 YES NO Swap CPU Board Do«a aervan look Uka Figure 3-6 Trace color circuitry oa CPU Board. Make cetain to cheek color delay circuit and a309 YES NO Swap-out Alll. Q107 on Motherboard Oo«9 screan look Go to KEYBOARD, Page 5-22 Uka F gure 3-5 NO Co to next page ATARI Home Computer 5-19 400 ANY VIDEO TaoUBLESHQOTING (contl Verify that each of the following levels and/or signal wave forms exist before proceeding to the ne« step. Use SAX-T II, COLOR BARS. locked into the continuous mode. Is there 3.58MHz osciXIation at R15S on Mother boaz4. Refer figure YES Is there input signal to base of gi07 Refer FLgur« YES la there output signal from coUectoi on QIQ7 Refer Figure YES NO Swap-out XlOl. Q103 and QI04 NO Trace circuit back to previous step NO Trace circuit back to previous step Is there signal at J107. Pin 1 Refer Figure NO Trace circuit back to previous step YES Go to next page ATARI Home Computer 5-20 400 ANY VIDEO TROUBLESHOOTING (contl JJ Ar« the foUowing present nefer Figure Hv on Modulator Pin S Signal on Modulator Pin 4 Signal on Modulator Pin Z YES Does screen look like Figure 3-S NO NO Trace circuit back to previous step J£^ Go to KEYBOARD, Page 5-22 CaU ATARI Tech Line Specialist Inside California (800) 672-1466 Outside California (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-21 KEYBOARD .STAR Press K and RETURN Do keyboard test YFS KX PASS YKS NO Did same keys fail as in PGWER-UP, PART I NO ALL YES Was it all or just some of the kevs SOME Replace keyboard 1 PASS - ( LL) NO Swap-out AlOl, 2103. and Z104 Go to TONE TEST.L^ Page 5-24 ] .XJi^ PASS NO Go to next page ATARI Home Computer 5-22 KEYBOARD (contl Troubleshoot . using foilowing information and Keyboard achematic. Page 5-3$ TYPICAL KEYBOARD OUTPUT Sample oaade from Z104, Pin U '^th W key depressed. SCOPE: rTT/DIV,.5oiS/DIV SYNC ; CHI, ♦ Trigger ltJ TYPICAL DECODER OUTPUT Sampie made from Z104. Pin 3 with W key depressed SCOPE ; TTV/DIV, .2mS/DIV SYNC ; CHI, * Trigger nn Pass JCSS. Go to TONE TEST, Page 5-24 MO CaU ATARI Tech Une Specialist Inside California (800) 672-1466 Outside California (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-23 400 TONE TEST MM] Entsr voice number to he tested (1-4) and Preaa RETURN Test remaining three voices YES Did you hear lU eight tones or speaker elicits* PASS iUl. YES NO ^The first t«o tones are very ■— — high in frequency: thus. they otay be inaudible to some ears. The TV speaker clicks from the OC level shifts can be heard for each tone. Replace POKEY (AlOl) and retest Go to CONSOLE SWITCH TEST. Page 5-28 PASS :££s. Go to START, this page NO Lock SALT II into CONTINUOUS MODE, restart test on VOICE I, and scope Pin 37 (AUD) of AlOl Go to next page ATARI Home Computer 5-2i^ 400 TONE TEST (cont) la there a frequency shift as the frequency of the tone lowers and amplitude decays to Ov SCOPE ; TTT/Div, .5mS/0iv SYNCj + CHI NO YES Presa J and RETURN Is the screen black with no sound NO YES P^'ess SPACE BAR Did you hear a single teat tone NO This re-runs the first two steps of this teat Go to 0, next page YES Press SYSTEM RESET, T. RETURN, 1. and RETURN PASS NO YES Go to CONSOLE SWITCH TEST, Page 5-28 CaU ATARI Tech Line- Specialist I Inside California | (800) 672-1466 Outside California (800) 53a-1535 (800) 538-1536 ATARI Home Computer 5-25 NO Are C164 (.luf). C179 (.luf). R161 (ISK) or R166 (6.8K} open YES 400 TONE TEST (cont) Repair and retest YES Repair and retest NO Are C184 (.OOIuf) or R170 (4.7K) shorted or open .xss. Repair and reteet NO Can you verify the following : 1) 4.SMHZ osciUation by connecting a scope to the emitter of Q105 2) A sine wave ^ Z.l centimetera 9 .lua/Dlv and 20mV/Dlv which equals s 4. 3MHz 3) Can you adjust LlOl to equal 4.SMHz YES Verify input to Audio Mixer by connecting scope ( .SmS/Div, 5mV/Div) to collector of Q106 Are wavefoma same as AlOl. Pin 37 (except wave- form is rounded, not square) NO Repair and retest No Return to START, Page 5-24 YES Is there output on LX18 (use scope (.5mS/Div,50mV/Div) NO Replace Q106 and retest YES Go to next page I ATARI Home Computer 5-26 400 TONE TEST (cont) Adjust A203 to Ch3. verify TV is tuned to Ch3 and fine tuning is adjusted to a elesr picture and turn the volume up Retest PASS iia YES Re-ma remainder of tone test for other three voices CaU ATARI Tech Line Specialist Inside California (800) 672-1466 Outaide California (800) 538-1535 (800) 538-1536 PASS NO YES Go to CONSOLE SWITCH TEST. Page 5-28 ATARI Home Computer 5-27 400 CONSOLE SWITCH TEST START Press S and RETURN YES ?ress aach (4) Console Switch PASS Go to ROM Test, Page 5-29 NO NO ,mi; Does console speaker "SEEP" when any Console Switch is pressed Are ail9 - R122 or CI21 - 124 shorted or open YES Replace and retest YES NO ^ YES Replace CTIA/GTIA (A301) on CPU 3oard and retest PASS Go to ROM Test, Page 5-29 YES ■ i NO Did a single switch fail NO Call ATARI Tech Line Specialist Inside California (800) 672-U66 Outside California (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-28 400 VERIFY ROM Press V and RETURN PASS Verify ROM Teat is locked into CONTIN- UOUS MODE and is displaying esch ROM checksum and the word PASS or FAIL NO Press D and RETURN Press E and RETURN Press C and RETURN Press V and RETURN QO)- NO Did ROM E faU NO Did ROM F fail NO □ id all ROMs faU NO I Swap-out Z401 - 2403 Go to next page YES Did ROM D fail i YES YES YES Go to RAM Test, Page 5-31 Replace A402 and retest Replace A403 and rettit Replace A401 and t retest YES Replace A401 - A403 and retest ATARI Home Computer 5-29 400 VERIFY ROM (cont) PASS YES Go to RAM Test, Page 5-31 YES NO l9 02 clock prttsent at Pin 10 of Z403 NO Trace 02 (Refer CPU Board on Page 5-10 ) , and retest PASS WO YES Go to RAM Test, Page 5-31 Call ATARI Tech Une Specialist Inside California C800) 672-1466 Outside California (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-30 400 RAM Press R and RETURN Enter the amount at RAM to be tested (Refer Page 3-12 ) PASS YES NO Press SYSTEM RE5ET The SALT II MENU is returned to the screen - it tells you how much RAM is resident. YES Did you select nwre RAM to test than is resident in the console c NO K UFJ Ga to RAM START Press and RETURN Press E and RETURN Press C and RETURN Press R and RETURN RAM TEST MATRIX is returned to the screen ( See Figure 5-2 and use the LEGEND provided in Table 5-t to decode failure ) Repair components and retest Go to next page Go to PORT Test, Page 5-33 ATARI Home Computer 5-31 400 RAM (cont) PASS YES Go to PORT Test, Page 5-33 MO Cail ATARI Tech Line Specialist Inside California (800) 672-1466 Outside Caafomia (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-32 400 PORT Press P and RETURN Install Hand Controller Jack teat connector and Peripheral PORT test connector Press RETURN PASS YES NO Bum -in Console for minimum of eight hours Reseat Test connectors and retest PASS YES NO Use Table 5-2 to dec .-it error matrix, :place and repair defective components and retest Go to next page ATARI Home Computer 5-33 400 PORT (cont) PASS YES NO Burn-in Console for minimum of eight hours Call ATARI Tech Line Specialist Inside California (800) 672-1466 Outside California (800) 538-1535 (800) 538-1536 ATARI Home Computer 5-3^ THIS PAGE INTENTIONALLY LEFT BLANK ATARI Home Computer 5-35 Table 5-1 CLOCK CIRCUIT PIN NUMBER BOARD CPU FREQUENCY 1-789 SCOPE CHART # 21 of JlOl 1 22 of JlOl CPU 1.739 2 3 of Z302 CPU 1,789 2 9 of Z302 CPU 1.789 1 10 of Z302 CPU 1.789 2* 13 of 2302 CPU 1.789 3 37 of A303 CPU 1.140 4 6 of Z301 CPU 1.789 3 34 of A302 CPU 1.789 3 35 of A302 CPU 3.579 5 29 of A301 CPU 3.579 5 23 of A301 CPU 3-579 6 Collector of Q102 300 Main Board 3.579 6 Collector of Q104 400 Main Board 3.579 6 7 of AlOl 400/300 Main Boaard 1.789 1 25 of A102 400/300 Main Board 1,789 1 * Use Scope Waveform Legend on next page to see illustration of waveform. ATARI Home Computer 5-36 I Scop« Havvforn i luS/DIV IV/DIV Scop* W«v«fora 3 Xufl/DIV IV/Biv X .< i( A A u U U Scop« Havvfora 2 lufl/DIV IV/DIV n Scop« Mav«fomi 5 luS/DIV IV/DIV Scopa Mavaform s lua/Dlv IV/nxv Scope Waveform Leqend ATARI Home Computer 5-37 Keyboard Connection Chart PIN CONNECTOR NUMBERS NUMBERS 400/Z102 40Q/J105 300/Z103 8Q0/J106 14 1 Z 13 4 13 12 5 -15 ! -7 -22 -30 -44 -23 -SO 10 — 9 1. -24 I -21 1-37 -36 ^T 11 Q AlOl — 6 -5 -20 -38 -35 .51 h49 •10 -L — 4 •23 J- -2S 1_ -39 -34 -52 -4a 12 13 13 -11 J- -12 L. -3 -27 -19 -40 -33 -53 -47 -la -41 -32 -54 -46 J- -13 M4 -I L- -28 -29 L. •17 -42 -31 L -55 -45 -16 -43 CONNECTOR NUMBERS 14 13 16 14 13 17 12 400/J103 800/J106 400/21 01 aoo/zi04 PIN NUMBERS Legend I. ESC 13. anuc 29. ssnon 43. CAPS LOWa 2. I 1 i< CU SCI 30. C8ZL 44. SHIFT 3. 2 17. q 31. A 45. Z 4. 3 13. H 32. S 46. X 5. 9 4 19, E 33. 47. G 6. 5 20. B 34. F 4a. V 7. 6 21. T 33. G 49. B a. / 7 22. f 36. H 50. W 9. 3 23. U 37. J 51. H 10, ( 9 24. I 33. K 52. • n. ) 25. 39. L 53. 3 ■■■ 12. < 26. P 40. 1 1 54. / 13. IHSERT 27. f,- 41, 55. /l\ 14. DKLEJZ BACK S 23, * , > 42. * j 36. SHIFT 57 . SPACE BAS ATARI Home Computer 5-38 ERROR COUNTER TEST COUNTER 0«l«ciiv« RAM Bevds 0«tec^«« RAM Idantifiar 0«f«ct [ndicatar B3|or a««nd B3 B4 and B« B9 and B6| or B4, B3 and B« 37; or 54 and B7 OMcription tnSKBkxdt 2nd SK Block 3rd SK Block 4tn SK Block 3th SK Block DiM«r«nc« Colunm DMcriptton SK 16K 00 zsn Ut2 Ot Z9U Z31t D2 Z310 Z310 03 ZJQI Z309 D« Z309 Z30S 03 Z307 Z307 06 2303 ZJOi 07 Z306 Z303 ATARI Home Computer Figure and Table 5-2 5-39 Table 5-3 Port Teat Legend A B C D £ F G M 7654 3210 ATARI Home Computer 5-i^O SECTION 6 SYMPTOM CHECKLIST The Symptom Checklist is designed to assist the experience technician arrive at a rapid diagnosis for problems. The checklist is not intended to replace the Diagnostic Flowchart as the primary troubleshooting guide, but rather, to supplement the flowchart. Each symptom is accompanied by some possible causes and the best point to enter the Diagnostic Flowchart to locate the problem. Symptom Possible Cause Diagram Entry Point Snowy Screen Black/Gray Screen Green/Yeilow Screen Solid Blue Screen No Color or Bad Color Bars with SALT 11 No Color Bars on TIA Test SW Box, AC Adaptor CH. Select SW, Modulator Adjustment, RF Cable Damage Verify -t-SV, -*V & +12V Power Supplies, CR20 1-209, C201-205, C210, A201, A302, A303, A301, A103, Alll, Z103-Z105, Q103-4, XlOl 2103-5, A03, Z303 & * all on ROM Board A101,Q107, XlOl R309 Adjust, A301-2on CPU Board; Alll, Ql 07 on Mainboard, XlOl, Q103, QIO* Modulator Adjustment A301 on CPU Board AA 400, Page 5-3 SOO, Page 7-3 BB 400, Page 5-4 800, Page 7-4 CC 400, Page 5-6 800, Page 7-6 DD 400, Page 5-7 800, Page 7-7 E£ 400, Page 5-9 800, Page 7-9 FF 400, Page 5-12 800, Page 7-12 GG 400, Page 5-12 800, Page 7-12 ATARI Home Computer 6-1 Symptom Possible Cause Diagram Entry Point No Gray Bars Upside Down Alpha/ Numerics or Player Field Some Keyboard Keys Faii AU Keyboard Keys Faii Tones Missing During Sound or Games Console (Game) Switches Will Not Function ROM Test Failed RAM Test Failed Hand Controllers Will Not Work A301, Alll, Q107 R309 Adjustment X101,Q103 & if Modulator A302 on CPU Board, A301 AU1,Q107 Modulator Keyboard Failure AlOl, Zl03ac* AlOi, R160, R161, R166, R170 C164, C179, CIS*, Q105 LlOl, Q106, L118, A203 A301 on CPU Board, RU9-122 C^21-12i^ AW I -403 on ROM Board 1*03 See RAM test Matrix, Figure 5 Table 5 See Port Test Matrix, Table 5 HH *00, Page 5-U 800, Page 7-1* n *00, Page 5-1 800, Page 7-1 * 13 *00, Page 5-21 800, Page 7-21 KK *00, Page 5-22 800, Page 7-22 LL *00, Page 5-22 800, Page 7-22 MM *00, Page 5-2* 800, Page 7-2* NN *00, Page 5-28 800, Page 7-28 OO *00, Page 5-29 800, Page 7-29 PP *00, Page 5-31 800, Page 7-31 QQ *00, Page 5-33 800, Page 7-33 ATARI Home Computer 6-2 SECTION 7 800 DIAGNOSTIC FLOWCHART The Diagnostic Flowchart is intended to be easy to use and the primary aid when troubleshooting the ATARI 800 Computer Console. Follow the prompts in the order presented. When a question is asked, follow the line from that box which best applies to the unit's situation. The flowchart leaves little to chance, it tells you when to perform a specific test and when to replace components. Swap Out Procedure At many places in the diagnostic flowchart, a box tells you to "swap-out" a chip or a number of chips in a particular order. The "swap-out" instruction means that you should replace the indicated components (one at a time) with a known good component of the same type. The 800 should then be tested with the new, known-good component in place to see whether the "swap-out" solved the problem being checked. If the swap- out did not fix the problem, the known-good component should be removed, and the original component reinserted. In this way, you avoid needlessly replacing good components- ° CAUTION: Extreme care should be taken when handling the integrated circuit chips. They are all v«r]t sensitive to static electricity and can easily be damaged by careless handling. Al2s^ keep the chips in their plastic carrier tubes or on conductive foam when not handling them. Make certain you are well grounded when handling the chips. Atari strongly recommends that you wear a conductive grounding band (which ties from your arm to ground) when handling the chips. The chips are also susceptible to damage from stress when being removed from or inserted into the sockets. Always use a chip-puller when removing the chips. Do not pry the chip out with a screwdriver or any other tooL Failure to follow the above guidelines results in unusally high chip faUure rates and extra expense- ATARI Home Computer 7-1 800 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS START Remove any Cartridge and Power-up Console YES Is a cieu- MEMO PAD on the screen YES Tesc special graphics mode of keyboard using Figure 3-1 NO Go to START, next page Pass Go to POWER-UP, PART II. Pane 7-8 " NO Note failures t co be keM 'board cast: ATARI Home Computer 7-2 800 POWER-UP CATASTROPHIC FAILURES AND SASIC OPERATIONS SNOWY SCREEN Is ths screen snowy YES Go to BLACK/GREY SCREEN, Page, 7-4 NO Repair Ji£S_ Is a clear MEMO PAD on the screen MO YES Go to POWER-UP, PART II, Page 7-8 Check, adjust, or replace AC power adaptor , channel select switch and TV switch box la a clear MEMO PAD on the screen NO Doee Power Supply Board. J201. Pin 17. have *5v YES Is there a good ground connection at Pin I of RF Module YES Is the RF Module mistuned or defective YES NO NO Go to Slack/Gray Screen, Page 7-4 Go to POWER-UP, PART IX, Page 7-8 Check, repair, or replace the following: CR206-CR209. replace 1N4001 type diodes with 1N5391 CC0I7988) Does voltage reg- ulator (A20Z) have t-Sv Check C208, C209, R203, and S202 - replace if defective Is a clear MEMO in the screen PAD prns NO Return to START this page ATARI Home Computer 7-3 800 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS BLACK/GREY SCREEN Is the screen black or gray YES NO Go to GREEN /YEUXW SCREEN. Page 7-6 MOTE I See Table 7 -1 . start at the top of it and trace back until clock signal appears, indicating which component has failed. Check Power Supply- Board for: Is there 'Sv on J201 Pin 1 YES Is there ■•■I2v on J201, Pin 21 YES Check the CPU Board for: Clock Circuit (see NOTE 1) Chip Reset Voltages: Is there ■♦^v on A302. Pin 36 and A303. Pin 40 YES Replace CTIA/GTIA {A301) NO Check, repair, or replace the following; Voltage Regulator CR204 and CR205 Replace 1N4001 type diodes with 1N539I (C017988) Check C203 - C205. and C212 NO Check, repair, or replace the following: Voltage Regulator (A201). CR204 and C203 - C205 ML Repair Is a clear MEMO PAp l YES on the screen P"^ Go to POWER-UP, PART II, Paffe 7-8 NO Go to C, next page ATARI Home Computer 7-4 SCO pcwsa-up CATASTRO PHIC FAILURES AND BASIC QPEaATIQWS 3LACK/GREY SCREEN (cont) On tha Mother- board Swap-out Clock Circuit components, ZlOl - Z104, and OS Board ROM F by substitution Is a clear MEMO PAD on the screen YES Go to POWER-UP. PART n. Page 7-8 NO Go to GREEN/YELLOW SCREEN, Page 7-6 ATARI Home Computer 7-^ 300 POWER-UP CATASTROPHIC FAILURES AND BASIC QPERATIONC GREEN /YELLOW SCREEN Is there a defective YES Repair RAM card tn the Unit (check lowest RAM slot first) C? NO ^ Swap-out ROMs A40I - A403 on Personality Board Is a clear MEMO PAD on the screen YES Go to POWER-UP, PART II, Page 7-8 NO Swap-out the following A303 , and Z303. and 2304 Is a clear MEMO PAI 1 YES Go to POWER-UP. on the screen PART II. Page 7-8 NO Go to SOLID BLUE SCREEN. Page 7-7 ATARI Home Computer 7-6 800 POWER-UP CATASTROPHIC FAILURES AND BASIC OPERATIONS SOLID BLUE SCREEN START Are the words - MEMO PAD on the screen YES Go to POWER-UP PART II. Page 7-8 NO Swap-out the POKEY (AlQl) chip Is the screen strictly Slack and White NO YES Swap-out A104 and XlOl on Motherbaord Is a clear MEMO PAD i NO on ^he screen I YES Go to POWER-UP, PART II, Page 7-8 CaU ATARI Tech Une Specialist In.-i-ie California (800) 672-1466 Outside CalifomiA (800) 538-1535 (800) 335-1536 ATARI Home Computer 1-1 800 POWER-UP, PART II Turn pow«r OFF, Insert SALT n Cartridge, and turn power ON Does screen look lilce Figure 3-2 See NOTE 2 YES NO Is there NO color or are the colors off YES Co to COLOR BAR Test. Page 7-9 NO NOTE 2 RAM: could be 3K, 16K, 24K, 32K. oe 40K TIA: could be NTSC or PAL ROM: could be - MATH:NTSA:NTSA MATH:NTSB:NTSB MATH:PALA:PALA MATH:PALfl:PALB ERR: is displayed for any bad ROM, verify error condition via VERIFY ROM. Page 7- Is the screen solid green , yellow , or . red YES Reseat SALT II Cartridge and retest NO Does screen look like Figure 3-2 YES Repeat ?OWER-UP, PART I. Pace 7-2 Go to COLOR I BAR Test. Page 7-9 I NO ATARI Home Computer 7-S COLOR BARS Does MENU appear (Refer Flgiare 3-3) YES Press C and RETURN 0o«9 screen look like Figure 3-4 NO Can you adjust R309 to the proper color YES Adjust a309 Does screen look like Figure 3-4 NO Repeat POWER UP, Page 7-2 NO NO Go to COLOR BAA TROUBLESHOOTING. Page 7-10 yg5 Go to TIA ?aae 7-13 Go to COLOR BAR TROUBLESHOOTING , Page 7-10 IS5- J Go to TIA. Pag>. 7-13 ATARI Home Computer 7-9 8QQ COLOR BAR TROUBLESHOOTING Swmp-out A301 And A302 on CPU Board Does 5cre«n look like Figura 3-4 NO Sw«p CPU Board Ooaa screan look like Figure i -4 NO Swap-out A103.