Panasonic TC-P50X3 (7) blink code

[zacheriaj]

Trying to diagnose this plasma. Gives 7 blinks when everything is connected indicating an SN fault. Disconnect the SN board and get 8 blinks indicating SS fault. I have tried to research a bit but i'm not finding issues for this model. This model has a TNPA5313 SN board and TNPA5312 SS. Can someone give me some direction or advice on common issues with this? Thank you!

[tw2005]

Re: Panasonic TC-P50X3 (7) blink code

I would say if you have a 7 blinker then the SN has shorted. You could just have a probe around on the IGBTs on the SN and see if any are shorted, maybe target ones marked 30F131 or DG301

Removing SN and getting 8 blink would be expected I suggest but I'd probe the transistors on the SS too just in case since the SS and Sn are connected to each other and there's a chance one can damage the other.

Shopjimmy has 1 board and it's cheap enough

[tw2005]

Re: Panasonic TC-P50X3 (7) blink code

has plenty of the SS too even if you got both around $60 is a cheap fix

[zacheriaj]

Re: Panasonic TC-P50X3 (7) blink code

I would say if you have a 7 blinker then the SN has shorted. You could just have a probe around on the IGBTs on the SN and see if any are shorted, maybe target ones marked 30F131 or DG301

Removing SN and getting 8 blink would be expected I suggest but I'd probe the transistors on the SS too just in case since the SS and Sn are connected to each other and there's a chance one can damage the other.

Shopjimmy has 1 board and it's cheap enough

In circuit, am I checking for short in its self or short against common ground?

[zacheriaj]

Re: Panasonic TC-P50X3 (7) blink code

Against common ground, I have three DG301s shorted. Q421, Q422, and Q423 on the SN

[tw2005]

Re: Panasonic TC-P50X3 (7) blink code

just see if there's a short between any 2 points of the 3 on those, so you have 2 legs and the metal tab which makes the 3 points of that part. They would normally be dead short when they fail, that's the most common way they go.

[zacheriaj]

Re: Panasonic TC-P50X3 (7) blink code

I find the three RFN10 transistors shorted across both main pins. The DG301s and 30f131s test ok in circuit.

[tw2005]

Re: Panasonic TC-P50X3 (7) blink code

I find the three RFN10 transistors shorted across both main pins. The DG301s and 30f131s test ok in circuit.

that's normal, well i'm not exactly sure what part blows on this SN then, could be a shorted buffer ic but 7 blinks should be a bad SN because SOS 6,7 is triggered by that board, having SN20 disconnected triggers 8 as far as I know. Either wait and see if anyone has first hand experience on this model or grab a SN while you can.

personally I'd grab both SS and SN purely because the SS is cheap and may reduce the risk of damaging the new SN if the SS has been damaged.

i.e. replace both at once.

[zacheriaj]

Re: Panasonic TC-P50X3 (7) blink code

Finally got some time to test further. When I plug the tv in with everything connected and press power on, the SN board has an LED that lights and dims to nothing within a couple seconds. During this time, you can hear the charging of a capacitor. I tested the FETs on the rail and found the two RF2001's are showing short between the two main legs in circuit. Is this a known issue? Or maybe not an issue at all?

[zacheriaj]

Re: Panasonic TC-P50X3 (7) blink code

Actually, it looks like the RF2001s are common cathode diodes so that should explain them showing short. Idk what else to test for. This is a customer tv who understands that I do this for a hobby and to learn. Does anyone have some component level advice on this SN board? I advised the customer against ordering the SN and SS board just in case the issue lies further than that.