Re: Tnpa5349ab

Thanks much for the reply, tvtimmy. Q600 is not shorted, nor are the other two transistors you indicated. I'm beginning to wonder whether we got some of those lovely fake IGBTs; there seem to be an awful lot of people that have had trouble with that issue. And FGD4536s are hard to find...

Re: Tnpa5349ab

I, too, have a TNPA5349AB in the shop that I’m scratching my head over (2011 model TC-P42ST30). The set had the (apparently) classic dead short across Vsus, with blown IGBTs at Q401-Q402 and Q421-422. I ordered a kit from ShopJimmy and replaced these four devices. Q441, D401, and D421 all appeared good under a diode test, and the gate resistors were also within tolerance, so the supplied replacements for these were not used.

Reinstalling the board (with the new screws) and applying power immediately took out the same components as before. No other...

Re: New Members - please post your introductions here

Hopefully I'm getting this right. I'm Don, and I work primarily in the automatic door industry. Lots of both firmware coding and hardware design, as well as doing some control repairs to keep things interesting. I'm an electronics engineer and have been soldering things together since I was five years old. Glad to be here!