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Discussion Starter · #1 ·
Anyone have any idea on what causes the set to have a series of green and white rectangles that fill the screen, No menu on screen display or anything just the checker board appearance. Thanks for any input. I am thinking the light engine but not sure how to diagnose the light engine.
Thanks
 

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If you can't get any menus that is a good clue that it is the light engine, but I have not seen that problem before. We have seen some odd patterns with no menus with a problem in the FMT board in the chassis. Can you post an image?
 

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Discussion Starter · #3 ·
Thanks for the input. I was wondering if the FMT could also cause something similar. I will post a pic of the screen next week before I open it up and check the FMT before trying the Light engine. Thanks again for the input.
 

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Hi, I have been fighting my own checkerboard issue for awhile now.. This was a freebie TV, so it's a spare time project..

I found approx a dozen capacitors swollen on the power board,FMT, and DM. Also one mounted backwards by a previous repairer.. I also found a blown 4 amp smt fuse on the FMT board..

After all the capacitors, and replacing the fuse it's better, but still has an issue..

Plug it in and wait for the blinking light to go out..upon turning it on I get the same checkerboard.. if I hit reset and wait again, then when I turn it on, It turns on and works great!!!

If I plug it in, wait, then hit reset, when I turn it on, it fires right up and no checkerboard!!!

I am guessing something is out of range and shutting down upon power up, for some reason it's close enough upon a reset to pass and function.. I have had it running for 6 hours with no issues and even with those high voltages..

Wondering if you could check voltages on the power board at the test points and post back here, my 6 volt is 7.03v and my 15 and -15 are both around 18volts.. I have been trying to correct those voltages as I am thinking that is my problem. Thought I had it today when I found C9A21 on the power board faulty, looked ok but measured at 6.4uf instead of the 10uf spec.. If the board is powered up by itself, the standby voltages were ok including the 6v and 15 and -15 but connected to the chassis my voltages spike for some reason.. I just don't want to chase this if this isn't the issue..
 

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I have never seen power supplies behave that way. My guess is that you will have to change a lot more caps if you are seriously trying to fix it. The problem is that you will have a hard time determining which ones to change. We no longer try to troubleshoot these chassis because Mitsubishi has been rebuilding them and rather liberal in accomodating customers on the cost.
 
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