I just picked up a Mitsubishi WS-65413 widescreen TV from a friend who just lost patience with it. The picture looks great - except for the fact that there is no red.
I did mess around with settings a bit just to see how it would look. I adjusted other colors, messed around with the balances, and it did look somewhat better. As expected, it did not come even close to a full vibrant color.
I took off the rear panel and covered up the blue and green CRTs. It is easy to see that there is some red coming out, and with the green and blue covered up I can clearly see the picture in red only. However, if I cover only one of either the green or blue CRT, and allow the other to run along with the red CRT, the red is completely drowned out. So the red is quite weak compared to the blue and green. Not sure if there is a power problem in supplying the red CRT or something else I can't conceive of as of now.
Has anyone seen this before? I do have the service manual ($6.50 on ebay - PDF) and I have plenty of experience with disassembly and reassembly of electronics along with lots and lots of electronic soldering.
I'm planning to take my trusty meter and start comparing the singals on the 3 CRT PCBs, but I'm starting with absolutely no rear projection TV debugging experience. I'm looking for any kind of assistance - suggestions of what else to check and/or where else to start.
I'm not going to take anything apart until I've found something definite to fix - or until someone gives me some guidance. Until then - I'll be probing with everything attached to see what I can discover.
I will definitely post whatever the results are of my poking and probing.
Just an update, I starting poking around the TV with my multimeter. Specifically, I probed the 13-pin component (which a pretty big heatsink) TDA6120Q on PCB-CRT(Red) as labeled in the service manual. I measured the voltage at each pin in order to do a comparison with the other 2 PCBs, which all hang in the front bottom of the TV. When I was finished probing - the red was full! I'm not sure what I did - and I feel that there is still something amiss with the set. I would like to make sure I didn't accidentally cover up some problem which will only become more difficult to fix down the road.
But as I type this - the red CRT seems to be working properly.
Another update. The red flickered out for about 5 seconds and then flickered back in. I'm now absolutely certain that there is something amiss. Does this sound familiar to anyone?