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Discussion Starter #1
I have a Mitsubishi WS55807 that one day simply did not turn on. It smelled like something electrical had burned from the back of the TV. I unplugged the TV for a few minutes and them plugged back in and it turned on with no problems. I tried shutting off and turning on a few more times, and sometimes it would turn on and sometimes not. Eventually after about 8 times turning on and off it wold not come back on anymore, and again a burning smell. I opened the back of the set and removed the circuit board and found pico fuse F9A06 blown. I carefully looked over (and smelled over) the entire board but could not locate any visible signs of damage. I went ahead and replaced the F9A06 7A pico fuse and the TV turned on without any problems. I shut the TV off and left the TV plugged in overnight and turned on in the morning without any problems. After work I came home and got the burn smell again when I walked up to the TV, and again the TV would not turn on (no green light, just nothing). I unplugged for a few minutes and turned on and the TV works great. Is see F9A06 is in the Standby Supply Regulator circuit ( I have a service manual), any ideas of what is causing the TV to be so intermittent in turning on?

DrJones
 

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These sets were notorious for coolant leaks from the CRTs. Look very carefully for corroded spots on the boards or wet spots.
 

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I did see some wet spots on the multi-component processor (IC2V00), so I cleaned and scrubbed with a good non-residual circuit board cleaner. The TV has been working great for about 4 months now and then decided shut off again today. Same symptoms, no green light, however this time I cannot seem to revive the TV by simply plugging and unplugging. I did a little troubleshooting and temporarily shorted the collector and emitter on transistor Q9A51 (which is the transistor hooked-up to the power button on the front panel) and the TV "turned on", but with no high voltage for the CRTs, but maybe some audio voltage because I could hear the speakers "pop". I performed a few voltage checks on the output of the Switching Supply Regulator (while temporarily shorting the emitter/collector) and see some strange voltages. I ordered a new Switching Supply Regulator from one of your recommended vendors, so I will try that when it arrives. I will post if it doesn't or does work. As always, your comments/suggestions are welcome.
 

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Discussion Starter #4
An update - A few months later I trashed the Mitsubishi and purchased a Panasonic TC-P65ST60 65" plasma and have been happy ever since :D
 
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