It looks that scope need service calibration.

If do adjustments it need follow _exactly_ Tektronix service manual. There are not words without meaning (even if it feels stupid..).



Also it need follow exatly this adjustment and calibration steps in the order what is prescribed in manual, this order is important and manual tell what steps can do individually (there are not many these steps. First you start power unit voltages and reference adjustment and CRT itself adjustments (linearity etc things) and if then change these agen, oh well...do full service cal agen. So, follow manual, do not jump over any thing exept if manual tell specially that it can do, in other case it is prohibited.. (This manual need read so that what can do can clearly read on manual and if there do not read some thing is accepted then it is prohibited - just opposite than many other books - example law.)

Do NOT separate adjustments without knowing exactly if it interfere somewhere to some other thing (only some things can separately adjust without calibration procedure. Cursors need adjust inside cal procedure and in given order of steps.

What tell me that it need adj and cal. Cursosrs looks like fully out of order. How is measurement accuracy?





How is this: "The power on message is "DIAGNSTIC. PUSH A/B TRIG TO EXIT", is this normal ?"



This is not normal!

This message tell that something is wrong (some rare cases it can do this once and reason may be "unknown" and in this situation it also can reset).

Normally it do not appear without reason! If this appear, it can continue to normal scope pushing a/b trig but now user know that something is maybe wrong and it also need read as: "do not trust measurements before problem solved."



(exept if someone do manually "bad start" example keeping some button pressed during start up prosedure.)



But in older 2465 (B models with new SMD HW I do not know) it can also appear if oscilloscope shut down procedure fails (it may happend example if some capacitor is bad in this clever power unit and there is not enough power to run normal shut down procedure after switch off or loose mains electric... This power up and power down "logic" can find in service manual. More serious case it may mean corrupted calibration or error in some circuit.



Becouse (in one your picture) cursors location is really bad it may tell that some calibration thing is not ok. (btw. now you have adjusted readings location without service calibration procedures - remember, they maybe now adjusted wrong and after (or better tell inside) service cal procedure you may need adjust also this agen).



Service cal must NOT START before sure that there is available all signals what need and just as they need be!

What ever step in procedure fails it can not continue AND id can not take back. There is no any "oops do not - take back" button after started cal prosedure (example vertical block) it need go from start to end and every step need just perfect cal signal from calibration generator and every step need adjust perfect becouse without this some other step may fail and it need do agen as long as it pass. (there is not "jump over" posibility -- oh yes there is is and result is what ever, maybe your cursors are from failed cal procedure if someone have not know what he is doing. Also in some things (some minor details) this manual is not very clear.



Note also. Always before full calibration need inspect power unit voltages AND ripple. They need be well inside limits what service manual tell. Selftest system give information what is wrong (what test number fails) but it do not know all. It do not know example if calibration data is wrong after some have done bad calibration.

This power up hours littlebit give feel that someone have reset system. If someone have done this, what other things he have done with oscilloscope in service mode.







