Panasonic TC-P42S30 issues

[Ccalxr]

Hi guys. I have a tc-p42s30 with a little bit of a different issue than I have been able to find with anyone else. The tv will power on normally, no blink codes. The panel lights up with large horizontal bars filled filled with think vertical lines. The audio will come one. I figure that the SN board (tnpa5349) is the culprit and like others I'm having a difficult time finding a new SN board. After doing some research it appears that some people have had success replacing the IC chips on SN board. I'd rather just replace the board but right now its not looking like much of an option. My issue is I really do not know how to test the chips to see which ones are bad. I can replace them myself, just need to find out which ones are bad. Can anyone tell me how to test these chips? I have attached a pic of the panel so you can see what I'm talking about and I also provided a link to a "repair kit" for this board. Please let me know if you have any insight for me here. I would GREATLY appreciate it.

http://www.ebay.com/itm/PANASONIC-TN...item2eccec8344

[tw2005]

Re: Panasonic TC-P42S30 issues

To put it simply, they short out . If you have a meter that has continuity or diode mode, set to that and any continuous beep will be a dead one. Could also measure resistance, pick any 2 pins, usually shorted across all 3 but try all combinations of the of pins to be sure .

Can you still access the other post and maybe delete the content? I just posted there, I'm going to edit it referring to this duplicate.

[Ccalxr]

Re: Panasonic TC-P42S30 issues

To put it simply, they short out . If you have a meter that has continuity or diode mode, set to that and any continuous beep will be a dead one. Could also measure resistance, pick any 2 pins, usually shorted across all 3 but try all combinations of the of pins to be sure .

Can you still access the other post and maybe delete the content? I just posted there, I'm going to edit it referring to this duplicate.

thanks. for some reason my original post will not allow me to edit or delete. I tried. If you can delete it that'd be great, thanks and sorry.

[tw2005]

Re: Panasonic TC-P42S30 issues

thanks. for some reason my original post will not allow me to edit or delete. I tried. If you can delete it that'd be great, thanks and sorry.

I'm just a user, just like you. It'd be admin job but I've never figured out how to contact admin when I've had a problem.

[tom66]

Re: Panasonic TC-P42S30 issues

I'd check -Vad and Vsc voltages on SN board.

[Ccalxr]

Re: Panasonic TC-P42S30 issues

I'd check -Vad and Vsc voltages on SN board.

sorry i dont really know exactly how to do that and i have an analog multimeter, im not sure if that makes a difference. my plan so far is to replace the mosfet and ic chips at Q401 Q402 Q421 Q422 Q441 D401 D421
IC502 AND Q53. from what ive read this should take care of it unless something more major. I tried to take some reading with my multimeter on the different mosfets and each give me a different reading but I really dont know which ones are bad and which are ok.

[Porky1]

Re: Panasonic TC-P42S30 issues

I'm experiencing a problem with the same set. I traced it down to the SN (some call it SC) board and find a short to ground on it's power connection. The boards are nowhere to be found so I am going to attempt a board level repair. Had the same questions about how to check the mosfets. Does anyone know if you can check them with them installed on the board or do they have to be removed?

[Porky1]

Re: Panasonic TC-P42S30 issues

One other question is whether you found a source for these parts. If you have, I would appreciate it if you would forward the location.

Tx

[Ccalxr]

Re: Panasonic TC-P42S30 issues

porky, so far this is the most complete "repair kit" i have found. there are others but they arent as complete.

http://www.ebay.com/itm/PANASONIC-TN...item232ffaec1b

[Porky1]

Re: Panasonic TC-P42S30 issues

Thanks I have an email into them to confirm the application of their kit to my problem.

[tw2005]

Re: Panasonic TC-P42S30 issues

They fail short cct so you could test them in cct as a quick guide however quite often they will be in 2 or 3s in cct so one bad one will short the others but when removed you sometimes may find not all are shorted.

[Ccalxr]

Re: Panasonic TC-P42S30 issues

well i got lucky and found a refurb board cheap. going to just swap the board and keep this one for a project later.

[SCITOMMY]

Re: Panasonic TC-P42S30 issues

Wait. I have the same exact TV. I ultimately had (4) shorted mosfets on the SN board, which caused the TV to not show a picture at all and give a 7 blink code. On these TV's, if there is a short circuit on any board, the Power Supply will shut down automatically and give a blink code to prevent further damage.

It's odd to me that yours would powered up normally if it was a shorted component(s) on the SN board.

[Ccalxr]

Re: Panasonic TC-P42S30 issues

yes i agree. i have not been able to find anyone else with a problem similar to mine, but its the only think i can think of. all pany's are supposed to throw a blink code when any board shorts, even the panel. this is bizarre.

[SCITOMMY]

Re: Panasonic TC-P42S30 issues

If your still getting a picture at all and the TV is running without a blinking code, then you should definitely not have a shorted component. On this model anyway.

Do you have anything hooked up to the TV at all?

[Ccalxr]

Re: Panasonic TC-P42S30 issues

no but when i have the cable box hooked up, i get sound. like i said, ive never dealt with a panasonic plasma that behaved like this. i thought a board at first but even a faulty a board will trigger a blink

[SCITOMMY]

Re: Panasonic TC-P42S30 issues

Yeah, I think you should be getting some kind of blinking code if it was a component on a board problem.

Have you tried reseating the ribbon cables that go from the panel to the SN board? You can try taking out the ribbon cable(s) and reseating them (where the problem is on the screen)

(Make sure you power down the TV first or you will short something out on the SN board if you do this with it powered up (like I did).

[Ccalxr]

Re: Panasonic TC-P42S30 issues

i tried that. same result. i wonder if there could be an issue with the a-board as well since its not producing a blink code.

[tw2005]

Re: Panasonic TC-P42S30 issues

do you have a manual? try service mode, then you can either try test patterns or I'd be tempted to try the mirror option and flip the display vertically and see if top goes black and bottom has that messed up display.

on these a dead short on the Vsus at power up does not produce a blink but a solid led.

It is possible to have a fault yet no codes as well, I've managed to create that situation on my TV.

section 6 are the instructions.

[SCITOMMY]

Re: Panasonic TC-P42S30 issues

Can you turn the TV off and on with the remote?

Have you tried holding down the power button for 10 seconds on the TV? Any blink code after that?

My next step would be pull out the P2 and P11 connectors on the Power Supply, power up the TV and see if you get a blinking light.