koolk
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Apr 17, 2007, 4:21 PM
Post #1 of 2
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Projection TV failure due to intent in design
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Hello,
I have a 52 inch Mitsubishi VS50607 projection TV that is 5 years old. Do manufacturers design these TVs to fail after about 5 years by the leakage of picture tube coolant?
I was watching TV when it turned itself off. I found an oily substance next the filter caps on the switching power supply. My initial thought was that the cap had leaked and shorted leading to the loss of the 12v standby supply. I fixed the problem, the TV worked for about 4 days and again failed. This time I found that my x-ray protection circuit had triggered the TV to turn off. I traced out the problem to the microprocessor input. The problem was a printed circuit land had been destroyed by an oily like drip from somewhere. I repaired it and cleaned the pc board with 91% isopropyl alcohol. The video circuits and receiver works but my TV no longer receives a broadcast. It only works with my VCR. I notice that my aft is standing steady. My schematics don’t describe how to test or what to look for in this part of the circuit. I read some books on TV repair telling me that it works like a phase lock loop. Can anyone suggest what I can try? I have also contacted the manufacturer to discuss what they can do for me. It seems that they know that the tubes can leak corrosive coolant. So, why didn’t they provide a shield on the boards? Why should I have to pay for this?
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