Panasonic TC-P55ST30

[Plurxtc1]

I have this model TCP55ST30 that has 14 blinks. The SC board is short and I ended up replacing all 3 DG301 from location Q401 Q402 Q403. At D421 there is RF1501 that was short on the diode test so I remove it out of circuit. The RF1501 comes up good out of circuit. Does anyone have any idea why my D421 is short?

[Biruslapio]

Re: Tcp55st30

I've isolated the SC board schematics from the P55ST30 service manual, but it's just a plain low-res image that cannot be read properly, seems there's more transistors connected to D421, Q421~423, could also be one of these white ceramic capacitors.

The IBGTs gate drivers also tend to fail when their respective transistors short, you have to fix everything or the board will die again.

https://www.manualslib.com/manual/19...c-P55st30.html

[tvtimmy]

Re: Panasonic TC-P55ST30

Take off the black heat sinks and check the igbts. You probably will find 3 more short. Also check Q600. It's a smaller one.

[Plurxtc1]

Re: Panasonic TC-P55ST30

@TvTimmy @Biruslapio you guys are right. Q421~423 was short. I got it fixed no more shorts. I'm gonna jumper to test the TV before attaching the buffers. Thank you for the quick responses.

[tvtimmy]

Re: Panasonic TC-P55ST30

You can glue the heatsinks back on with Locktite gel control super glue. It works great. Let us know how it turns out.

[Plurxtc1]

Re: Panasonic TC-P55ST30

I have white thermal glue that I pasted on the heat sink. I'll let you know tomorrow when I see my client.