Re: Panasonic Plasma TV TX-P50X50B - Shorted power supply



Yes, it certainly seems to be the only thing wrong.
The fault started out being periodic with typically a week or so between breakdowns.
Finally the fault matured and stayed permanent.
So, it wasn't such a big thing finding the defective switching-chip.
It was identifying what could be used as a replacement that proved difficult....

Re: Panasonic Plasma TV TX-P50X50B - Shorted power supply

OK, I see no-one's interested.
However, just in case someone ends up here from a Google-search or the like, I'll give some feedback on how this has ended.

Obviously replacing the original 7-pin FAN6755U with a new 8-pin ditto wasn't an option.
It seemed more reasonable trying out the NCP1271 chip even if I haven't found any docomentation as to this chip being a drop-in replacement for a FAN6755U.
Not really surprising as the pin-out is different from the 6755U EXCEPT on the Darfon schematic....

Re: Panasonic Plasma TV TX-P50X50B - Shorted power supply



Darfon SMPSU schematic for Panasonic TX-P42X50E

Thanks for the schematic diagram.
I have a couple of questions:
This TV doesn't have stand-by 5V power as the switching-chip FAN6755U does nothing.
It's most likely defective as the surrounding components tests OK including the series string of resistors to facilitate initial start-up.
Now, here's the problem:
The schematic diagram shows pin-7 to be NC (Not Connected).
In fact it's missing on the original...