Question about Toymax Magnavox 37MF331D 37 in. LCD TV

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Powers on and off all the time like a thermal switch is tripping when I put a fan behind it it stops

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It may be a safety thermistor component inside tripping as it overheats just as you suspect - working like an electrical fuse, but responds to heat instead. They can go faulty and start turning the power off too soon

Another possible cause is a dry solder joint (very common problem). It's ok while cool, but after a few minutes of being on, the heat in TV causes the tiny solder break to widen just enough to switch it off.

If you can leave it on with the fan blowing on it, and it does keep going on & off without you touching it, then i'd say it's 95% certainly a thermistor.

If it turns off, and you have to turn it back on manually (it goes onto standby or off completely), then it could be either, causing the problem.

Another final thing I see as possible is, the screens inverter can be heating up and going off (the TV will stay on really, but the screen will go black as if it's off, and when cooled even slightly it can turn back on again. You can check this easily by putting a bright lamp close up to the screen. The picture will still be there, but very very dark - a flat light gently touching against the screen will allow you to just about see the TV picture.

(the screen inverter is a special high powered circuit that takes a lower voltage (usually about 12 volts) and converts into a huge amount needed to work the powerful bulbs in TV screens.

Posted on Nov 10, 2010


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GE JVM1870 Spacemaker Microwave Fan Malfunctioning when Cooking

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This fan does not automatically come on when you cook with the microwave.

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If the thermal device is a thermostat, it will reset when it cools down, and the oven will work.

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You can usually find helpful exploded view diagrams and order parts by entering your full model number here.

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We're happy to help you with free advice and we'd appreciate your thoughtful rating of our answer.

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