Dear All,
I am struggling with this unit for some time.
The waveform at TP305 is correct, according to the manual.
However I can not obtain more than 5 steps at TP-306.
I have checked the voltage at U305B-3 which should "define" the maximum number of steps and it varies from 0.05 to 4.75V , as expected.
Just as a desperate measure I have alredy replaced U305, U220, U350, Q306 and Q324 without success.
I have created a photo album with the waveforms at TP-305, TP-306 , tthe 577 display as well as the pertinent schematics sheets.
See
/g/TekScopes2/album?id=279289.
Any help will be welcome.
Thanks,
Roger
