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54540A Display module problem - screen filckrs

Question asked by sp2xdm on Feb 8, 2012
Latest reply on Feb 9, 2012 by sp2xdm
Hello everyone.
Can anybody help me providing schematic of display board incorporated in HP54540A ? It will be very useful in localisation the source of weired and realy irritating malfunction of the monitor module.

Marking on the monitor PCB label:
TYPE J260194 HP P# 2090-0324
Serial No 000884  MI08M
HITACHI MIZUSAWA ELECTRONICS LTD

Deflating and synchro circuit bases on uPC3179C. I have problem with filkering screen (it seems to rapidly kick upward for a blink of the eye every few seconds, once or in series) It causes in irritation and drives me mad all the time I'm using it.
I cannot locate the faulty element. I've replaced all electrolytic capacitors on the display borad trying to find a dry one, but it didn't help me to recover the display from this fault.
Replacing var resistors used for regulate V-LIN, V-Size and 1uF Cer/MKT? cap in vertical oscilator didn't help too.
It's not a problem with PSU (I've tried to use external lab PS to supply display board directly, removing glass fuse- it consumes about 1,3A @12V. Powered form independent PSU behaves as the same unstable way as in orginal state), and i've resoldered all components in deflection circuits.

Have you simmilar problem in the past?
It will be a good idea to look for replacement uPC ICS ?
I didn't want to replace components one by one till the moment i will replace all of them... But i should find the faulty one.
Scope is almost useles now, scrren filickrs too frequently to focus the atention on the trace...

Regards
Mike  

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