View Full Version : I got a whine


toxcrusadr
05-16-2010, 08:07 PM
No, I'm not whining, my TV is. It may not qualify as 'vintage' - it's a '93 model 35" Mitsu - altho these days maybe it does.

I had it fixed several years back when (according to the repair shop) a capacitor crapped out in the power supply. He said they used pretty cheap ones. I don't remember what the symptoms were, seems like it would not run at all.

Now I have a whine, sounds like 5 or 10 KHz. It's getting worse. Comes through the audio, not from the set itself so it's not something in the CRT. I can run it on an analogue output from my digital cable box, or from the remaining analogue channels still on my cable, and it's the same. I haven't tried it on just an antenna, but I don't have a convertor box so I couldn't tune anything anyway.

Just wondering if this is a sign of more bad caps - like a shunt cap to ground is open allowing noise through. I could attempt a recap of the power supply, I can solder and identify caps well enough, and can probably find the PS. I don't have a service manual or schematic. Probably a crapshoot...whaddya think?

holmesuser01
05-21-2010, 12:09 PM
That set probably gets the B+ for the audio section off the flyback. It goes through a small diode, and a 1 ohm resistor used as a fuse. Then, there are some caps for filtering. It's not too bad if you have the schematic to follow.

I used to work on alot of Mitsubs when they were younger. Your set is a pain to move, but I never saw one with a bad kine. Your problem with caps was the typical problem.

Findm-Keepm
05-28-2010, 06:09 PM
Model #? I have a huge database of symptom/cures fo Mitsubishi sets, and may be able to help. Does it have MTS audio? The MTS audio board was famous for problems on these....


Cheers,

Findm-Keepm
05-28-2010, 06:31 PM
Cheers,

toxcrusadr
01-08-2011, 10:23 PM
Forgot about this thread...the set ended up crapping out not too long after that, brightness went to crap on top of the audio whine. Eventually hauled it to the one man shop down the road, he had it two months before he could get to it, but was right on schedule. 4 little caps. Whole thing cost me a Benjamin but way less than a new TV. It took till now to get the cable TV situation sorted out but now I have a good channel selection on the basement TV again. Only half way through winter! At this rate I may catch up by the time I croak.

radiotvnut
01-09-2011, 01:30 PM
Most Mitsubishi TV's from the late '80's and newer had a severe situation with bad caps. Often, these caps would leak all over the PC board; which, created a big mess to clean up and often ate through PC board traces. I've actually junked some of these because they had so many bad, leaking electrolytic caps. In recent times, I usually turn down any Mitsubishi that is brought to me for repair.

toxcrusadr
01-10-2011, 09:00 PM
I've had this fixed twice since '93, and both times it was caps. Next time it will probably be time to junk it, all 200 lb of it. I'm in no mood to move it out of the basement again! :-\