Panasonic CT-32HX40B H.O.T. problem

Jul 26, 2007 5 Replies
A

I have a Panasonic CT-32HX40B HDTV. Some time ago, the flyback transformer died, and I replaced it. Since then, there is no picture when I turn the TV on. I know it's tuning the channels correctly because I can hear the channel's audio through the speakers. I thought to check the horizontal output transistor and found that the base and emitter are both shorted to ground. Does anyone know what could cause this, or what components to check? Any information would be a great help.



Thanks, Adam Dorsey snipped-for-privacy@gmail.com



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M

Base-emitter junction would normally read shorted because of the drive transformer. Even out-of-circuit most HOT's have a 47 ohm resistor internally across the E-B junction.

Your problem is elsewhere - maybe a 200 volt line down. You can check the voltages at the driver transistors on the crt board.

Mark Z.

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G

Video and horiz blanking circuits

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A

Thanks for the info.

I probably wasn't clear enough when I said this. The transistor is fine; what's shorted is the base and emitter pads on the board itself. It seemed weird that both pads were shorted to ground on the board. The pads are laid out like this:

o C B-o o-E

and B and E are both shorted to ground. Is this normal?

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A

Thanks for all the help guys. I think I've found the problem and will be doing more checking tomorrow (it's late).

Thanks again for all the info!

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