The fault will definitely occur when the machine is turned on for the first time after it has not been turned on for a long time.
After a failure occurs, the host will return to normal after a period of time.After normal testing, all functions are accurate.
I did the full troubleshooting checklist test and below is the video of the test.I tested TP201 and TP3 waveforms,Please watch carefully, the second half of the video is when 8920a returns to normal state from fault state.If you need TP1 and TP2 waveforms please let me know as it is inside the metal shield and requires lead output to test.
I think the fault seems to have nothing to do with the signal input,If you have any better suggestions please tell me
Thank you for your help