Panasonic TH-P50ST30A Not turning on, no error code!

[Beavisjem]

Hi guys,

I'll give a little back story for my problem.

I have a Panasonic TH-P50ST30A that is 2 years old and after a big storm the other day (Brisbane, Australia) the Tv turned off. When I initially notice the TV wasn't working. (out in the garden sorting something out) The display was blank and the green light was on.

I switched off the TV to avoid being damaged by the storm. After the storm passed I tried turning the Tv on and only heard the relays click but nothing on the Tv no picture, no blinks, no power light nothing.

The Tv was plugged into a surge protector and so was everything else connected to the Tv. Surge protector has been tested and no surge was detected.

It seems that the cable modem that was connected to the Tv via RJ45 cable was fried in the storm (classic burnt circuit board smell on the modem) The modem didn't get a direct strike but rather had a brownout moment in the storm and it fried.

Anyway I think the Modem sent a voltage to the Tv via the RJ45 Cable (modem runs at 12v DC)

Could this have broken the TV

Diagnosis

Decided to take the back off the TV and have a look, nothing obvious, no caps bulging, tested the power board and I am getting voltage, so I am assuming the power board is ok.

It seems that the Main A board is not telling the TV to turn on due to it being defective. The fans don't come on and neither do any picture/sound/power light

Are there any other things I should test before I look at the possibility of a replacement A board?

I am also having issues finding the correct board, I have the service manual for the TV and I have put the board number in several places and not been able to find the correct parts.

Any help would be much appreciated. If you need anymore information please let me know

Cheers
Chris

[tom66]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Try unplugging SN and SS -- if error code changes, typically to 6,7,8 blink you may have a shorted SS/SN board

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Just in case it's not storm related, disconnect SC2 (Vsus from the SC board) and try powering on. SC boards short out , There's a 2011 guide with some flowcharts getting around this forum if you search the US equivalent models.

I'll have a dig later, after dinner.

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

I just pulled the back off and tried what you said.

I disconnected the SC and via power and ribbon cable and no change. Just the usual relays clicking.

Just so I know what I should disconnect and which board I am messing with, here is a picture from Panasonic of the back of my TV with the boards labeled that I am using.



I don't see an SC2 board? But I tried what you said with the SC

Thanks for the help so far

Chris

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Probably worth mentioning this too. I think revised consumer laws came into effect for out of warranty claims. These have a fairly widespread issue with the SC so you may try Panasonic for the repair based on the new law which you'll have to check out for yourself.

Once you open it up this is probably voided but if you can do it without any evidence of tampering like burring the heads of the screws you may get away with it.

http://www.abc.net.au/news/2011-06-0...rights/2749924

i don't know if it was 2011 or 2012 that it was revised but may be worth investigating.

Either way with a brand like panasonic and the price of these, I'd try it.

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Try unplugging SN and SS -- if error code changes, typically to 6,7,8 blink you may have a shorted SS/SN board

Hi Tom,

Which one would be the SN board?

Cheers
Chris

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

What Tom and I are suggesting is Vsus could be dead short on either the SC or SS. I was quoting the connector on the Sc, SC2 with the brown and white leads from the PSU. can be 200V there and there will be residual voltage there after a power cycle so avoid reconnecting straight away.

[tom66]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

On this, SN = SC.

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

There's no SN in this size, 42 has a SN which is combined SC,SD,SU on a single board.

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Just disconnect the power to the boards? Or the power and the ribbon?

Chris

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Once you open it up this is probably voided but if you can do it without any evidence of tampering like burring the heads of the screws you may get away with it.

Hmm I had it open several times, so chances are slim. Not that the screws are burred but they show signs of being undone.

Thanks for the advice anyways

Chris

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

Right just tried disconnecting the power from both the SC and SS, plugged it in and turned it on and the same result.

No lights, nothing, just the usual relay click.

Chris

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

I don't have much more for you , could be A board.

For US market, see if page 33 makes any sense for your model.

[Beavisjem]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

I don't have much more for you , could be A board.

For US market, see if page 33 makes any sense for your model.

I'll check the problem solver on page 33 from the manual you provided tomorrow.

Just looking into the future, any idea where the best place to source a replacement A board?

Cheers
Chris

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

I'll check the problem solver on page 33 from the manual you provided tomorrow.

Just looking into the future, any idea where the best place to source a replacement A board?

Cheers
Chris

Can you work out the board number and revision? Should be a TNPH number or actually there may be a white sticker on it. Could be TXN/A etc.

That doc you grabbed from Tom, does that have your exact model in it with the board numbers?

Prime electronics Bowen Hills, i ordered an OEM EEPROM for an A board from them. I think Jenny? They know their stuff. Hopefully they'll help out but $$ could be expensive.

Contents insurance for lightning/power surge? I could have claimed for a hit in Darwin but the Suncorp excess made it pointless especially for myself when I can do a fair amount of self repair and I've built up a little stock pile of boards for my 2010 model so I rather keep it. getting a newer and even less reliable panasonic plasma was not attractive for me.

By the way I'm not a professional TV repairer, had some fun with a few sets though.

[tw2005]

Re: Panasonic TH-P50ST30A Not turning on, no error code!

I found the same doc in Toms library and your model is showing in that so the A cold be tztnp01naua which a google brings nothing up.

The PCB should also have a TNPHxxxx and a 2 letter suffix stamped on it somewhere. I think if ordering though the TZTNP01NAUA will be what Prime will need. But they should work it out with the model number too.

You'd have to confirm it. You may get lucky and one of these TVs may pop up on Ebay but nothing I can see now.