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Discussion Starter #1
Hi,

I have a Mitsubishi HD1080 (Model #WT46807). The convergence problems were fixed about 4 years ago. Now the convergence "drifts" only in the corners, and needs to be re-adjusted every other month.

My local service tech told me he could fix it for about $350 (and upgrade to the higher wattage chips at the same time).

Now I find that the left channel output on the variable output sound has 'greatly' reduced output (not totally dead though).

My question is this: 1. What would an estimated repair cost be? 2. Can I get a repair manual and repair parts and fix this myself? I would love an excuse to replace it, but now is a "really" bad time to do it.

Thanks for any and all help you can provide. I look forward to returning to a 'normally' functioning set...

Arana
 

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If the drift is only in the corners, the problem is likely not the output ICs but one of the low voltage supplies, 5v or 9v, perhaps. You could be seeing aging out of some of the caps in the set, so some troubleshooting is in order. This is likely beyond the ability of most DIYers. I'd be getting out the scope and ESR meter. You can get a manual from Mitsubishi or one of several sites on the web, but make sure that you are getting everything. Some of the download sites do not have the full manuals.
 

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Discussion Starter #3
Thanks for the info. I'd have to dust off the scope, I haven't used it in years, and the last time I repaired a TV it had vacuum tubes, and I was about 10 y.o.! Does it make sense to just replace the supply module?

Can you give me a hint on the audio? I can suffer through the convergence, waiting for better days, but the audio makes life tough, since that means I can't use the remote for volume control anymore (they always seem to boost the volume during the intense parts, which wakes up the kids! ;-).

I was hoping that there was just a simple audio amp (module/IC) that I could replace and limp along with the rest until I either replace the set (in my dreams!) or get the money to repair it.

Most of my experience is in digital electronics, I did some audio in High School, but that was mostly op-amps and discretes...
 

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Like I said, I would be looking for some failing caps on the regulators for the low voltage supplies. Check the supply voltages and look for instability or noise.
 
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