Quote:
Originally Posted by karmaman
Hey guys, there's a pretty big transistor, Q505, that shares a heatsink with Q901 and Q902. According to my multimeter it is shorted, now I haven't taken it off the PCB to test for sure, but every other transistor gave me correct readings without taking it off the PCB (won't have time to fully test it until tomorrow). According to the schematic, Q505 is responsible for H OUT. I'm very hopeful that this is the problem. Fixing this monitor has engulfed me for the last 5 days, it's all I do with my spare time, and I have finals this week :/ probably not very good to be working on a monitor instead of studying. Anyway, if Q505 IS shorted, and it's responsible for H OUT, it would probably be causing the problems I am having right now, amirite?
EDIT: According to the service manual, Q505 is a 2SC5530-01, a Hitachi part. There is no NTE cross for it. I know for a fact Radio Shack won't have it (they never have anything) and I don't think Fry's has it either. Can you guys recommend a replacement that will work? It is a Bipolar NPN transistor, not sure of voltages or anything. I also have a 15" Trinitron in the attic, any chances it might have the same part and I can pull it off there? Will check tomorrow and let you guys know. I'm feeling hopeful right now! There's no way I can pitch this monitor now, I've put about $14 worth of new capacitors in it!
BTW MRX37, thanks a million for the link to the repair manual. Without that, I would have pitched it by now.
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Q505 sounds like it's VERY likely to be your problem.
Input the part number into google and see if you can order it online.
The 15" trinitron is unlikely to have that specific transistor in it. It might, but don't get your hopes up.
If you can get a replacement, test the resistors and caps around that transistor. It's likely that a bad resistior or cap made the transistor fail, and you wouldn't want to put in a new one just to watch it fail 5 minutes after you power the monitor up.
EDIT: you're welcome, and I'm glad I could help.
Being the owner of a 19 inch Viewsonic flat screen CRT monitor that had intermittant HV failure when I first found it, I know fixing a monitor is not fun, but it's damn rewarding when you fix it.
EDIT 2:
I think this is your part.