Need help for Panasonic TC-P42GT25

[rogerpjr]

First, let me start out with that I have virtually no electronics experience so any answers need to be pretty non-technical. I have a Panasonic 42" plasma TV, manufactured in Sept. 2010 that suddenly stopped working. I get no picture and sound and a 10 blink code on the red LED. When I turn the power on, I get a loud click from the power supply board (I assume a relay) but nothing else. The service manual I downloaded said it could be one (or more) of four boards, either the SC, SS, A or P boards. I have already replaced the A board as that was one of the boards needing replaced on my 58" Panasonic plasma TV, but that didn't help. The manual says to look for an LED on the SC and SS boards and if they are not lit the board may need to be replaced. I see no lit LEDs on either. Of course, I can't find a SC board, but the others are available for about $50 each.

What I need to know is if there is a way for a non-technician like me to be able to check the other boards easily to see which may need to be replaced. I was really wondering about the P board since it makes such a loud click when power is supplied, but maybe that is normal. Also, is there a good source for a SC board or a place to get mine repaired?

Any help you guys can give would be appreciated so I won't be wasting money replacing boards I don't need to replace.

[tw2005]

Re: Need help for Panasonic TC-P42GT25

First, let me start out with that I have virtually no electronics experience so any answers need to be pretty non-technical. I have a Panasonic 42" plasma TV, manufactured in Sept. 2010 that suddenly stopped working. I get no picture and sound and a 10 blink code on the red LED. When I turn the power on, I get a loud click from the power supply board (I assume a relay) but nothing else. The service manual I downloaded said it could be one (or more) of four boards, either the SC, SS, A or P boards. I have already replaced the A board as that was one of the boards needing replaced on my 58" Panasonic plasma TV, but that didn't help. The manual says to look for an LED on the SC and SS boards and if they are not lit the board may need to be replaced. I see no lit LEDs on either. Of course, I can't find a SC board, but the others are available for about $50 each.

What I need to know is if there is a way for a non-technician like me to be able to check the other boards easily to see which may need to be replaced. I was really wondering about the P board since it makes such a loud click when power is supplied, but maybe that is normal. Also, is there a good source for a SC board or a place to get mine repaired?

Any help you guys can give would be appreciated so I won't be wasting money replacing boards I don't need to replace.

We had a 46" with the same issue on this forum last week or so. SC board is the most common failure of this series. If you go through this you'l find a training guide to help diagnose this.
https://www.badcaps.net/forum/showthread.php?t=50380

You could try searching either your model or tnpa5081 and there's going to be plenty of threads to read. 10 & 4 blink are probably the most common blinks on this for shorted SC board.

According to this doc, Sc is most common for 2,3,4,6,7,10 blink codes.


How non-tech are you? Can you operate a multimeter or own one?

Since you had 10 blink and replaced A board and still have 10 blink I'm inclined to just tell you to replace the Sc board.
The only problem is ideally the SD & SU boards should also be checked for shorts just in case. Otherwise you may end up spending $120 on a board and blow it up again. generally they're ok but it's a gamble and I've lost that gamble on one of these once.(unlucky)

If you have a multimeter and know how to check for shorts or continuity then a quick and easy would be to find transistor Q661 and simply measure across any 2 of the 3 legs. If the SC has failed this transistor is pretty much assured of being dead short.

As far as repair goes I'm not sure who to suggest now that Moduslink has stopped.

There's a couple of repairers on Ebay. Quad City I helped him work through some fault finding so I'd say if he's offering a repair service he's on top of it now.

maybe your fellow countrymen can offer better local knowledge.
When searching watch the part numbers or board suffix as there are numerous TNPA5081 revisions to suit 42-54" and then there's 3D specific versions too.

Pretty sure the 42" use all the same version

TXNSC1LGUU or TNPA5081AH

[rogerpjr]

Re: Need help for Panasonic TC-P42GT25

I do have and can use a DVM and have even assembled a few kits many years ago, but that is pretty much the extent of my electronic knowledge. I'll see if I can figure out where Q661 is located. If it is shorted. what readings should I get? This model doesn't have SD & SU boards, but does have a single SM board which I guess probably replaces the other two. Also, it is a 3D model (which I haven't used).

[tw2005]

Re: Need help for Panasonic TC-P42GT25

I do have and can use a DVM and have even assembled a few kits many years ago, but that is pretty much the extent of my electronic knowledge. I'll see if I can figure out where Q661 is located. If it is shorted. what readings should I get? This model doesn't have SD & SU boards, but does have a single SM board which I guess probably replaces the other two. Also, it is a 3D model (which I haven't used).

The image I put up has it marked. Yes of course, Sm ,I forget as i have the 50"

So what's the highest resistance this meter can go to?

Readings, well in Ohms maybe 0 or lead resistance so could show a few ohms or if it has a continuity buzzer or diode mode it should just beep constantly

[rogerpjr]

Re: Need help for Panasonic TC-P42GT25

The meter is a Fluke 77 that is about 25 years old. I have no idea what it can do but I'm sure it will be fine as I got it when I worked for a computer company as a parts tester, but I'll have to download a manual or spec sheet for it to find out exactly. It is auto ranging and does have an audible continuity checker as well.

[tw2005]

Re: Need help for Panasonic TC-P42GT25

The meter is a Fluke 77 that is about 25 years old. I have no idea what it can do but I'm sure it will be fine as I got it when I worked for a computer company as a parts tester, but I'll have to download a manual or spec sheet for it to find out exactly. It is auto ranging and does have an audible continuity checker as well.

perfect , I have a 73, I would not bother it's probably good to 30meg and better than what i see some have here.

Set it to diode and probe 2 legs, also set to ohms and place across sc2.

I thought you said you had no electronics experience

[tw2005]

Re: Need help for Panasonic TC-P42GT25

Yours and mine LOL.

[rogerpjr]

Re: Need help for Panasonic TC-P42GT25

Really don't have much electronics experience. It doesn't take much knowledge to take a strip of incoming parts and test a bunch for values or set an assembly on a fixture to check if it works. Hopefully I'll get time to check the SC board board tonight or tomorrow night.

[rogerpjr]

Re: Need help for Panasonic TC-P42GT25

Just checked the Q661 and it seems to be OK. When I checked SC2 across both legs of the connector I averaged 0.384 M ohm. From one leg of the connector to ground is 0.2 ohm and from the other leg to ground was about 2.2 M ohm. Does this mean the SC board is probably good? Any thoughts on whether the SS or P board would be causing the problem?

[tw2005]

Re: Need help for Panasonic TC-P42GT25

Just checked the Q661 and it seems to be OK. When I checked SC2 across both legs of the connector I averaged 0.384 M ohm. From one leg of the connector to ground is 0.2 ohm and from the other leg to ground was about 2.2 M ohm. Does this mean the SC board is probably good? Any thoughts on whether the SS or P board would be causing the problem?

Well, I think I've been here before with someone else in EUROPE with a 42GT25 with a similar scenario that went bad as I think they ended up blowing their replacement SC so I'll tread carefully.

Those results seem to indicate it may be ok, not what i was hoping for.

You can try this. Disconnect SC2, SS11, p35, the 3 white ribbons connected to the A board. power it on and see if it completes the startup with no error blinks.

If so that would suggest the P and A are ok. Also if it does you could back probe P2 and check vsus is on (around 200V). Could also check the other voltages too but on do it for about 30secs or it will probably shutdown with a 4 blink error.

Do Not reconnect the p2-sc2 , p11-ss11 or p35 straight away as there will be residual voltage and if p35 arcs that goes to the panel and could blow the chips on the ribbons that connect to the c boards and that will be terminal PDP damage.

leave it 5mins or use the meter to check(DC) that the voltage has dropped off all of those.

This will probably be a drawn out process but I'd be inclined to check everything.

Do the quick check for shorted vsus, P15v and vda as shown in that training guide.

isolate the SM including the 4 Vfg bolts and measure resistance as shown for Vfo, Vscn_F and 5V_F. You'll have to report what you get as I don't know with a SM board what to expect.

You could isolate the sm, remove the 4 vfg bolts, jumper SC50 and see if it turns on with no errors.(if this happens stop here)

You could simply follow the 10 blink after power-on flow chart.



Assuming the Sc is ok, A is ok, Sd is third on the list of probability so that may mean SM in this instance.

[rogerpjr]

Re: Need help for Panasonic TC-P42GT25

Sounds like a challenge for this weekend!

[RedRocket204]

Re: Need help for Panasonic TC-P42GT25

I have the exact same model, TC-P42GT25, and will be troubleshooting my problem in the coming week while I'm off work and have some extra time. Glad to see some valid info on the same model number. I have looked at the other thread linked here and downloaded the troubleshooting document.

[RedRocket204]

Re: Need help for Panasonic TC-P42GT25

Forgot to add, and BTW, not able to edit the above post... maybe it's because a first post or ???

My TC-P42GT25 actually has had minimal use as it sits in the basement for the kids to use but they really don't use it much at all. Not impressed with Panasonic's reliability here. Be that as it is... would like to get it fixed and not have to replace.