Panasonic Plasma TC-P50S2 Lightning Dead

[hrpuffnstuff]

Had a lightning strike 2 weeks ago. I think it came in through the OTA antenna or the cable tv cable based on the fact that the items that were damaged were TV, media players, cable modem, wireless router, and antenna amplifier. When the lightning entered the house the TV was turned on and made a loud pop. Anyway, my Panasonic plasma TC-P50S2 is completely dead. Dead as in when I press the power button there are no lights (such as standby) and no noise (such as clicks or relays), and absolutely no sounds of life. I've got the back cover of the TV and, after reading many threads on this forum, have come to the conclusion that it's the P board, A board, or both. If the A board were bad, which contains the power switch, presumably nothing would occur if I pressed the power switch. And if the P board were bad, I'm not sure what would happen if I pressed the power switch. I have a meter and do get 120V where at the connector coming from the power supply to the P board. Anyone know how I can narrow this problem down to confirm which or if both boards are bad? Thanks so much for the help.

[TVRepairNoobie]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

Check Fuses F201, F501, F601, F602.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

Yeah, how do you check those fuses? I've never seen those types. They are white with colored bands...how would you know if they are bad other than removing them from the circuit and seeing if they are "open"? By the way, while still soldered to the board, they measure .4 or .5 ohms...none are open...

[TVRepairNoobie]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

Set your DMM on continuity test on the 4 fuses in the picture shaded red, if it doesn't beep, it means the fuse is bad.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

While still soldered to the board, they measure .4 or .5 ohms...none are open...all beeped

[Andrew F. Ali]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

hrpuffnstuff...well you have to be a certain age to know this character and then there was WitchiePoo always planning something evil....like probably this lightening strike.
Anyway do you know how to solder and use the DMM? IFyou can then I can give you a procedure to test the Power Board then that way you'll save gussing time and determine if the Main Bd is the culprit. However, when you look at the underside of the Power Bd d0 you notice if any of the copper traces are burnt out?

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

lol...yes...living island was just a great place for an 8 year old to spend a few minutes on saturday mornings...yes, I know how to solder and use dmm...when you say underside of the p board do you mean back side, as in with it removed (because I have not removed it yet) or do you mean the bottom of the board? I went ahead and pulled the board, the back (the joint side) looks good.

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

A board is quite vulnerable with lightning especially the HDMI ports, I've seen photos of components blown up or burnt around those. Check if 5V stdby is available at either A7 or P7 pin1, if so the A board is dead because from there the A board then uses that to power the front LED via a regulator. may want to isolate P7 too if there is not 5v stdby and check again in case the A board at A7 pin 1 is shorted.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

thanks tw...I think that means put dmm meter on "DC" and check for voltage with the positive lead on A7 or P7 pin 1...where do i put the negative lead...is there a good place to ground the negative lead (chassis, a place on the board, or some other place)?

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

thanks tw...I think that means put dmm meter on "DC" and check for voltage with the positive lead on A7 or P7 pin 1...where do i put the negative lead...is there a good place to ground the negative lead (chassis, a place on the board, or some other place)?

chassis or any of those board bolts that have earth pads under them and yes DC 5v. since something went pop, there may be a visual burn on that A board or component with a hole in it's head.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

i've got 5v dc at p7 pin 1

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

Well the A board has an issue.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

okay...so is it possible to troubleshoot the A board and replace bad parts (i suppose there could be many) or better to replace the whole board? Also does further trouble shooting need to be done on the A board to confirm that it does not have other issues? Or does the 5V standby test tell us that all is well with the A board?

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

okay...so is it possible to troubleshoot the A board and replace bad parts (i suppose there could be many) or better to replace the whole board?

maybe but beyond me, a few have tried and failed, some have got lucky and located shorted components in the HDMI circuits and isolated those and got the TV running. Mixed bag really.

I think before you start digging I'd first check out what's available used first as it may turn out these are almost extinct so you may have to send it off to someone like moduslinkpts for a rebuild . That'll mean that core board needs to be intact.

pay close attention to the Board revision it is important. There will be many A boards with the same number for both the HD models and the FHD models but only 1 version will suit this

[Andrew F. Ali]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

Do as tw2005 suggests That way you will probably determine is the A bd is defective. However if you are getting on connector P7 at pin1 5Vdc that is a good sign too.
Here is away to self test the P Bd so you can be absolutely sure it is good.
Build a test-jig by connecting two (2) 220V 100W light bulbs in series so that the two (2) wire ends can be connected to a circuit.
Follow these steps in order:
1. Disconnect all the connectors to the P Bd, except the AC input connector.
2. On connector P7 connect a1kOhm resistor across pin 1 (StBy 5V) and pin 5 (F-StBy-ON).
3. Connect another 1kOhm resistor across pin 1 (StBy 5V) and pin 7 (Panel-Main-ON).
4. On connector P35 connect a wire to bridge pin 1 and pin 3.
5. Connect the test-jig across connector P2 ( Vsus output voltage and chassis GND).
6. Apply the AC and the test-jig should light up.
7. Measure the DC voltage across connector P2, it should read approx. 192 Vdc.
8. Observe the intensity of the test-jig. If it starts to dim then there is a problem with the P Bd. If the intensity remain then the P Bd is OK.
9. Measure the other output voltages on connector P7 15Vdc etc. (Nerves of steel required)

NB: a. Be careful not to short any pins on P7 when making solder connections.
b. Look at the connections for shorts and rectify before applying AC.
c. be careful DMM probes do not slip while making voltage readings.
d. If Step No. 8 passes the test then confidently diagnose the A Bd as defective.
Good Luck and remember BE CAREFUL!!

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

okay...so is it possible to troubleshoot the A board and replace bad parts (i suppose there could be many) or better to replace the whole board? Also does further trouble shooting need to be done on the A board to confirm that it does not have other issues? Or does the 5V standby test tell us that all is well with the A board?

tells me the P board is at least producing standby voltage, from there the A board should then have the front LED lit, which it does not, and the F15v and relay clicks, also not present.

A board is dead in my opinion.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

First, thanks to all who have contributed to this thread! To confirm, consensus is
1. A board is bad
2. P board is producing 5v which is a sign of life but can be tested using Andrew Ali's test above to confirm it is functioning
I found a used A board for about $150 usd. Is it better to buy that board or have moduslinkpts rebuild. I have no idea what the cost of that would be.

[Andrew F. Ali]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

It may be less costly to repair the A Bd. The choice really is economics and yours to make. My choice however is to buy the used board. Regards.

[tw2005]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

First, thanks to all who have contributed to this thread! To confirm, consensus is
1. A board is bad
2. P board is producing 5v which is a sign of life but can be tested using Andrew Ali's test above to confirm it is functioning
I found a used A board for about $150 usd. Is it better to buy that board or have moduslinkpts rebuild. I have no idea what the cost of that would be.

yeah, it's a personal choice. where did you find a board?

http://www.moduslinkptstvboards.com/txn-a1lquus/
$116.77

http://www.moduslinkptstvboards.com/...return-policy/
PURCHASED / REPAIRED TV PARTS WARRANTY POLICY:

We offer a 6 month warranty policy for items purchased from or repaired by ModusLink PTS. If you wish to return your purchased part for credit, please see our return policy below.

[hrpuffnstuff]

Re: Panasonic Plasma TC-P50S2 Lightning Dead

love the conversation and advice!!! i'm looking for the link right now for the $150 board...by the way that first moduslinkspts link that you cited takes me to a sufix AC board...mine is a sufix AB board...my guess is that it makes a difference