Panasonic P42G20ES

[Mtgtnt]

Hello everyone.

Family members Plasma decided to stop working and they took it to a technician that told them it would be 400 Euro to repair. I told them I will look at it even though I haven't done any electronic work in 20 years I still figured I can grab the service manual and look up the code the power light was giving.

Now before I start replacing boards (not going to test mosfets and caps) I did a lot of reading here and through the manual. Here is my findings:

When turning it on, I get the relay clicks as normal and the green light flashes.
The green light turns off and the red light starts blinking.
4 blinks.
Disconnect P2: 7 blinks.
Disconnect P11: 4 blinks.
Disconnect P35: 4 blinks.
Disconnect P6: 10 blinks.

I did not disconnect more than one at a time.

Is there anything else I should check to be sure its only the P-board? Is there any tips in how to test for any of the other boards be faulty also?

Thanks for everyone's time reading my request.

[tw2005]

Re: Panasonic P42G20ES

Blown SC board, there's a cheap board in Europe assuming it's ok.

[tw2005]

Re: Panasonic P42G20ES

All going well ,should fix this for 15% of what you were quoted. The SC can be repaired so you may want t keep it and have a go, use the good board as a template.

It's not a P board fault(not normally)

[tw2005]

Re: Panasonic P42G20ES

........When turning it on, I get the relay clicks as normal and the green light flashes.

The green light turns off and the red light starts blinking.
4 blinks. PSU SOS, PSU has dead short from SC board

Disconnect P2: 7 blinks. Vsus line to SC2(SC board TNPA5081AH), change of status because shorted Vsus removed

Disconnect P11: 4 blinks.Vsus to SS board, but Vsus is still shorted at SC, hence no change

Disconnect P35: 4 blinks.Vsus is still shorted at SC, hence no change

Disconnect P6: 10 blinks.missing voltages so A board produces 10 blink....................................................

[Mtgtnt]

Re: Panasonic P42G20ES

removed....

[tw2005]

Re: Panasonic P42G20ES

Part numbers you can search are, TXNSC11NEK42 , TNPA5081AH & TXNSC1LGUU.

Also search TNPA5081 in badcaps and I have a fair bit of info based on the 50" model Sc board.

[Mtgtnt]

Re: Panasonic P42G20ES

Great! Part paid for and on its way.

How do I go about doing a resistance test on the P-board?

Been a long time since I did this and all I have is a multi-meter.

[tw2005]

Re: Panasonic P42G20ES

Great! Part paid for and on its way.

How do I go about doing a resistance test on the P-board?

Been a long time since I did this and all I have is a multi-meter.

P board should be fine, the buffer board needs checking to safeguard blowing another Sc just in case it failed too which can happen. I'll have a look because these have a SM (Sd/Su combined). Quick test is to put the meter in diode mode and place one probe on the earth plate on the buffer board and then slowly run the other along the face of each contact pin at the buffer output ribbons. You do not want to see any dead shorts.

There is a 3 point resistance test i do which is covered in a training guide i like for my 50" which we should be able to use or maybe the S2/S20 series which ahs the same buffer but smaller Sc boards.

[tw2005]

Re: Panasonic P42G20ES

slide 90, has Sm board test

your TV

[tw2005]

Re: Panasonic P42G20ES

This is for the G20/25 series, i have not checked if this has SM tests but better fault finding in this as is mentions SC as a probable and most likely cause for 4 blink.
https://www.badcaps.net/forum/attach...6&d=1383456126

Slide 43 you could use the pinouts on the buffer boards for the same test, they have a third checkpoint compared to 2 in the other guide,

post up your results for us to see.

[Mtgtnt]

Re: Panasonic P42G20ES

Perfect. As soon as I have all these tests done, I will post the results. May take me a little while as its lunch time and have to deal with making lunch for family. (National Holiday today)

[tw2005]

Re: Panasonic P42G20ES

Perfect. As soon as I have all these tests done, I will post the results. May take me a little while as its lunch time and have to deal with making lunch for family. (National Holiday today)

Lucky you. I am curious, how is your english so good?

[Mtgtnt]

Re: Panasonic P42G20ES

I am an expat from US. Been here since Feb 2006.

[tw2005]

Re: Panasonic P42G20ES

I am an expat from US. Been here since Feb 2006.

Fair enough, it's funny the people you get to chat with. That explains everything, just had me curious talking to someone with perfect english in Slovakia

[Mtgtnt]

Re: Panasonic P42G20ES

I have tested the SM board pins 1 and 5.

My meter only has 2M-Ohm check so not possible to see the 4M-Ohm resistance.

When testing Pin 1, reading started around 900K and moved past the 2M limit in less then 2 seconds.

When testing Pin 5, reading started around 200K and moved past the 2M limit but at a slower rate. It took around 5 seconds.

I did a second test but both read Open right away so I let it sit for a few minutes before testing again. Results were exactly the same.

Also to note that my battery light came on shortly after my first test. I will pick a new battery up tomorrow and to the test again just to make sure.

[tw2005]

Re: Panasonic P42G20ES

I have tested the SM board pins 1 and 5.

My meter only has 2M-Ohm check so not possible to see the 4M-Ohm resistance.

When testing Pin 1, reading started around 900K and moved past the 2M limit in less then 2 seconds.

When testing Pin 5, reading started around 200K and moved past the 2M limit but at a slower rate. It took around 5 seconds.

I did a second test but both read Open right away so I let it sit for a few minutes before testing again. Results were exactly the same.

Also to note that my battery light came on shortly after my first test. I will pick a new battery up tomorrow and to the test again just to make sure.

You know I've seen this before but the info in the S2 series SM test is incorrect.

Pin 1 4Meg could be correct but Pin 5 , 190K for 5V_F is incorrect. probably why your meter went out of range. If you cross reference to the other G20/25 series 5V_F is over 5 meg

Test pin 2 and I would expect 220k

Then go to connector SM41

Test
Pin 2 VFO expect over 2 meg (4meg)out of range
Pin 4 VSCN-F expect 220k
Pin 8 5V_F expect out of range over 2 meg (5.7Meg)

[tom66]

Re: Panasonic P42G20ES

I think it's also worth testing for shorts from each of VFO/VFG to the output pins.

I've had a buffer board (in an LG) with no shorts between the equivalent of VFO/VFG, but it had a short between VFO and the top most output pin.

It was pulling down Vsc supply, lucky no damage to Y-sus, but on a Panasonic, it can damage the SC.

[tw2005]

Re: Panasonic P42G20ES

I think it's also worth testing for shorts from each of VFO/VFG to the output pins.

I've had a buffer board (in an LG) with no shorts between the equivalent of VFO/VFG, but it had a short between VFO and the top most output pin.

It was pulling down Vsc supply, lucky no damage to Y-sus, but on a Panasonic, it can damage the SC.

Have not struck that yet with these, but all for being thorough

[Mtgtnt]

Re: Panasonic P42G20ES

I have finished testing all pins of SM41/42/46. All were out of range except SM41 pin 4 and SM42 pin 2. Those were exactly 220k.
Some took a while to go out of range, while most were oor right away.

http://youtu.be/NQtSXVgTUIg

[tom66]

Re: Panasonic P42G20ES

Does your meter have a beep function where it will make a sound when the probes touch?