I hate these as much as anyone else who has worked on them. Not really hate, but you know what I mean.
Set comes in with the 80 volt supply shorted, turned out to be an electrolytic. That feeds the T&B pin ckt, so originally I thought the transistors were shorted but no. Found the old C914 in the PS causing overvoltage. So I got the high voltage back up but now there is no video. There is OSD, and you can just barely see something when changing channels. There is also no audio.
This may be unrelated but the convergence won't align. The error is constant on the whole screen but the DC levels are out of range slightly.
Power supply seems good. But then it had this overvoltage condition. On the standup boards I've checked the regulators, everything seems OK. I have video going to the jungle, and into the video amp IC, the AN91A14 or whatever. I have checked just about every blamking line I can find, including the spot killer just in case the audio problem is unrelated, but the collector of that transistor is low. In fact all blanking seems to be OK, by the waveforms they give.
The audio output is OK, and the fact that there is no sound is starting to lead me to think it is in the muting that runs when you change channels or sources.
I go on the premise that the customer did not watch the TV without audio or video until those caps went bad. Did the overvoltage condition cause this ? I think it likely, but I just can't find it,,,,yet.
Anybody experienced on the V12 chassis, does this ring a bell for you or anything. Any pointers would be highly appreciated.
JURB