JP1 Remotes

[hillbillybill]

I have a Panasonic CT 32D10B chasis # DP341 that turns itself off ever so often. I suspect it might be overheating as it comes back on after a few minutes. Most of the time when it shuts down is within a few minutes after it is first turned on and will go off two or three times and after that it may or may not go off again for several hours. On some of the channels there are light stripes across the picture at the top of the screen.
There is an NTE 2353 Horizontal Defl output w/ damper diode. Could this semi conductor be the culprit?

[zaphod7501]

I'm not very familiar with this set but the NTE is a substitute part (not original) which could indicate previous repairs for similar problems. Bad solder connections on the bottom of the main board are a generic source of the type of situation that you describe but I don't know exactly where to direct you.

I might be able to track down the correct part (horz out) but not until I consult another tech next week. The substitute transistor could be the problem but there is probably another trouble. (which caused the NTE to be needed in the first place)
_________________
Just call me Zaphod (or Steve) --- I never should have started using numbers in a screen name but I just can't stop now.

[underquark]

Could there be a PSU problem as well (leaky electrolytic capacitor)?

[zaphod7501]

I believe his set is about 8 years old.
The power supply is a high frequency switch-mode and is part of the main board. Further complicating troubleshooting is the oddball design. The main power supply and the horizontal output is connected to the Hot part of the chassis but the micro, drive circuits, vertical, audio, etc are connected to the Cold side of the chassis. The high voltage transformer is also an isolation transformer and there are numerous other devices that isolate the Hot from the Cold circuits.

Troubleshooting intermittent shutdown and startup circuits is almost impossible without previous experience or Factory support of the specific set. I didn't find anything usefull on misc sites, like techlore or fixya.

The recent spate of power supply filter fixes has made it possible to fix some of the otherwise disposable flat panel TVs but generally wasn't a big problem 10 years ago: and the surface mount capacitor failures didn't become a big TV problem until the HD-Ready sets appeared around 2002-2004. They were a problem in camcorders and PIP circuits almost exclusively until then.
_________________
Just call me Zaphod (or Steve) --- I never should have started using numbers in a screen name but I just can't stop now.

[hillbillybill]

Thanks for all the replies. The original part is still in the tv set. I gave the cross reference NTE part as I figured it would be easily identified. The part checks out to be good.
I pulled the pc board out as far as I could without disconnecting any wires so that I might better identify any part that mat be overheating. In doing this the tv began shutting down very frequently. Upon touching and moving the pc board the set toggled off and on as I put pressure on the board. Therefore, I believe most certainly the problem will either be a bad solder joint or a cracked trace.