Using the CROSH diagnostics on your Dell Chromebook

Refer to the sections for guidance to the CROSH diagnostics, how to use them on a Dell Chromebook and information about resolving charging issues.

The Chrome OS does not support ePSA, Dell BIOS, the F12 boot menu or DellConnect. There are no preboot diagnostics. All troubleshooting has to be done from inside the OS. Chrome Shell (CROSH) and the Chrome URL commands provide some troubleshooting tools, information, and advanced settings.

Chrome Shell (CROSH) is a command line interface similar to the Linux BASH or Windows command (cmd.exe) terminals. Chrome OS is based on Linux, but CROSH does not recognize most Linux commands.

The most useful commands for troubleshooting would be memtest, storage_test_1 and storage_test_2, ping, and tracepath. Ping works differently than it does in Windows. By, default it repeats until you hit Ctrl+C, and it does not show any statistics. Tracepath is similar to the Windows traceroute command. A detailed explanation of the commands can be viewed below or by typing help or help_advanced in CROSH.



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Note: The CROSH is the Chrome shell which allows you to run tests and other command line functions similar to Windows cmd.exe or Linux BASH Terminal.

To open the SHELL follow the instructions below:

Open up the Chrome Browser.

Press the Ctrl + Alt + t keys together. The interface should appear onscreen.

(Fig.1 A Terminal Window onscreen)

Type in the CROSH command for diagnostics. Type 'help' for a list of available commands. Type 'help_advanced' to display a more complete list of commands for debugging purposes. alternatively you can refer to the list of commands below.

Note: Dell does not support running the system in developer mode or installing an alternate OS, e.g. Chrobuntu and Crouton.



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The Tables below list the available commands in CROSH.

Help Commands Command Purpose exit Exit Crosh Shell help Display this help. help_advanced Display the help for more advanced commands, mainly used for debugging. ping [-c count] [-i interval] [-n] [-s packetsize] [-W waittime] < destination >

Send ICMP ECHO_REQUEST packets to a network host. If < destination > is "gw" then the next hop gateway for the default route is used. It works just like the ping command on other operating systems. Press Ctrl+C to stop the ping process or halt any other command in Crosh. ssh [optional args...]

Starts the ssh subsystem if invoked without any arguments.

"ssh < user > < host >", "ssh < user > < host > < port >", "ssh < user >@< host >". or "ssh < user >@< host > < port >" connect without entering the subsystem. ssh_forget_host Remove a host from the list of known ssh hosts. This command displays a menu of known hosts and prompts for the host to forget. top Sets the chapsd logging level. No arguments will start verbose logging.

Help_Advanced Commands Command Purpose battery_test [< test length >] Tests battery discharge rate for given number of seconds. No argument will default to 300s test. bt_console [< agent capability >] Enters a Bluetooth debugging console. Optional argument specifies the capability of a pairing agent the console will provide; see the Bluetooth Core specification for valid options. chaps_debug [start | stop | < log_level >] Sets the chapsd logging level. No arguments will start verbose logging. connectivity Shows connectivity status. experimental_storage < status | enable | disable > Enable or disable experimental storage features. ff_debug [< tag_expr >] [--help] [--list_valid_tags] [--reset] Add and remove flimflam debugging tags. memory_test Performs extensive memory testing on the available free memory. modem < command > [args...] Interact with the 3G modem. Run "modem help" for detailed help. modem_set_carrier carrier-name Configures the modem for the specified carrier. network_diag [--date] [--link] [--show-macs] [--wifi] [--help] [--wifi-mon] < host > A function that performs a suite of network diagnostics. Saves a copy of the output to your download directory. network_logging < wifi | cellular | ethernet > A function that enables a predefined set of tags useful for debugging the specified device. p2p_update [enable | disable] Enables or disables the peer-to-peer (P2P) sharing of updates over the local network. This will both, attempt to get updates from other peers in the network and share the downloaded updates with them. Run this command without arguments to see the current state. rlz < status | enable | disable > Enable or disable RLZ. rollback Attempt to rollback to the previous update cached on your system. Only available on non-stable channels and non-enterprise enrolled devices. Please note that this will powerwash your device. route [-n] [-6] Display the routing tables. set_apn [-n < network-id >] [-u < username >] [-p < password >] < apn > Set the APN to use when connecting to the network specified by < network-id >. If < network-id > is not specified, use the network-id of the currently registered network. set_apn - c Clear the APN to be used, so that the default APN will be used instead. set_arpgw < true | false > Turn on extra network state checking to make sure the default gateway is reachable. set_cellular_ppp [-u < username >] [-p < password >] Set the PPP username and/or password for an existing cellular connection. If neither -u nor -p is provided, show the existing PPP username for the cellular connection. set_cellular_ppp -c Clear any existing PPP username and PPP password for an existing cellular connection. sound < command > < argument > Low level sound configuration. Can be used to play/record audio samples and enable beam forming on Pixel.

"sound beamforming < on | off >" will enable/disable the feature.

"sound record [duration]" will start recording.

"sound play < filename >" will play the recorded audio samples. storage_status Reads storage device SMART health status, vendor attributes and error log. storage_test_1 Performs a short offline SMART test. storage_test_2 Performs an extensive readability test. syslog < message > Logs a message to syslog. tpcontrol {status | taptoclick [on|off] sensitivity [1-5] | set < property > <value>}

tpcontrol {syntp [on|off]} Manually adjust advanced touchpad settings. tracepath [-n] < destination >[/port] Trace the path/route to a network host. update_over_cellular [enable|disable] Enables or disables the auto updates over cellular networks. Run without arguments to see the current state. upload crashes Uploads available crash reports to the crash server. wpa_debug [< debug_level >] [--help] [--list_valid_level] [--reset] Set wpa_supplicant debugging level. xset m [acc_mult[/acc_div] [thr]]

xset m default Tweak the mouse acceleration rate. xset r rate [delay [rate]] Tweak auto-repeat rates. The delay is the number of milliseconds before auto-repeat starts. The rate is the number of repeats per second. xset r [keycode] < on|off > Turn auto-repeat on/off. If keycode is specified, it affects only that key. If not specified, it affects global behavior.



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Note: You should always keep the charge on your battery above 1%, letting the battery completely discharge can be harmful to your computer and the battery may not charge from a completely discharged state.

Open up the Chrome Browser. Press the Ctrl + Alt + t keys together (Crosh will open in a new browser tab). Make sure the A/C adapter is plugged into the Chromebook and into an electrical outlet. Type battery_test 1 (including the space) into crosh, and then press Enter. Look for Battery is Charging (percent left). Note: This shows that the AC adapter is charging the battery. Remove the A/C adapter from the Chromebook. Type battery_test 10 (including the space) into crosh, and then press Enter. Note: This runs the test for 10 seconds. Look for Battery health: (with a percent showing). Notes: A Battery health percentage over 50%, means the battery is performing as it should. When the battery does not seem to be charging When you have not already done so, perform the following steps : Try another A/C Adapter if one is available. Try following the steps outlined in the following article: How to recover and reset the Chrome OS When after performing the preceding steps and the battery still will not charge, Contact Technical Support.



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