Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

[Chaks]

Slightly cracked Panel ( 2 inch 'X' shaped crack on the left bottom side) got hit with a golf ball

Plasma Panel lits up with white screen for 2 seconds and shuts down with 7 red blinks ( blinking repeats with a 3 second pause)

Here is the link to the Panasonic Plasma TV TH-P42XT50D PCB Images of my TV.

https://drive.google.com/folderview?...Hc&usp=sharing

Hoping someone can help me diagnose the problem

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

just for you,I'll copy and paste.

Photos of everything except the panel fault and crack. I'm thinking chances are the panel is stuffed unless this has a fascia glass panel in front of the screen but if it shut down with 7 blinks after impact then, the impact was enough for panel shorted, also means the buffer board most likely shorted , also means SC also maybe bad but if the screen fires up briefly Sc could be ok. maybe the gas has not all leaked out yet but i think it's probably all over for this TV.

there's no glass fascia, the crack is the PDP cracked.

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Thanks tw2005.
Is there a way to test the buffer board (integrated sc,su,sd board ) if they are ok.
Why I am asking is a second-hand plasma panel is available at a local seller for my tv model but he wants me to purchase it first (non returnable). $300 for the panel alone and for installation I have to manage myself.
If the (sc,su,sd) boards are ok then I may buy the panel ... otherwise I have to sell the TV at a scrap value.
(I had already overturned the tv on the table before I thought of posting on badcaps.net so I could not take a snap of the cracked panel.)

[tom66]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Can you attach the boards to his panel to test it?
If the boards are already bad there is no harm - it will just not work.
It is not possible for bad boards to damage the panel as it's basically just glass - assuming Vda is OK (check on your set) but that would be very unlikely anyway.
I don't know what the prices are like in India but $300 for a panel seems too expensive, surely a new TV will be cheaper.

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Thanks tw2005.
Is there a way to test the buffer board (integrated sc,su,sd board ) if they are ok.
Why I am asking is a second-hand plasma panel is available at a local seller for my tv model but he wants me to purchase it first (non returnable). $300 for the panel alone and for installation I have to manage myself.
If the (sc,su,sd) boards are ok then I may buy the panel ... otherwise I have to sell the TV at a scrap value.
(I had already overturned the tv on the table before I thought of posting on badcaps.net so I could not take a snap of the cracked panel.)

I should have known but these later models have a SN board(sc +buffers)

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Thx tom66 and tw2005
If the SN board is bad then there is no point in spending for the panel. I bought this tv in June 2013 for $850. The new panel from panasonic will cost me $500 today that's why I opting for a used one I can further bargain but the retailer will not sell me below $275.
Plasma or led tv of 42 inches today cost between $800 to $900 here in India.

Unless I find a way to test the SN board and possibly replace defective diodes and ic's on the SN board I am stuck. This tv was manufactured in jan 2013 and you can see panasonic have updated the pcb design substantially. All test points defined in this forum for issues similar to my tv .... I don't know how to apply to this new SN board design.

( the local seller of used plasma panel does not allow me to even test at his place)

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Some update on my broken tv.
I disconnected the SN board (power + ribbon cable) and switched on the tv.
... I was greeted with a white screen and a low volume hiss sound from the speakers ( similar to ... when we switch on the tv without an input signal ). This time the screen was lit for close to 5 seconds before shutting off and the led started blinking 6 times ( six times ).

Some comfort that the panel was lit for 5 seconds and the hiss sound. I am waiting for someone to help me diagnose the SN board at the test point markings found on the pcb.

All the three DAF30A's have dead short at 1 & 3 ( image su-sc-sd-13 ).

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

I was thinking , disconnect the panel ribbons from both the SS and the SN, but have the SN connected as normal, fire it up and see if it stays on.

What I don't know is if doing this can pop a board. I've done this once on a LG plasma with no damage to the boards(had cracked screen) to prove them.

The newer manuals are too hard to blow up as they lose resolution and I,m not 100% sure. All i can suggets is the first option at your risk or check resistance across SN2 and then find the Test point SRV VFO on the SN , place one lead there and then slide the other slowly across the face of each pin connector at the SN panel ribbon connectors and see if there is a dead short on ay of those, use diode mode or whatever beeps.

that's the best I can do having not seen or tested a SN before like this.

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

DAF30 sounds like a diode? are you saying pin 1 & 3 short if you test between the 2? = normal, common cathode, anode - anode = short cct

[Alastair E]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

In your first line, you say--

Slightly cracked Panel ( 2 inch 'X' shaped crack on the left bottom side) got hit with a golf ball...........

Can you confirm, that its just the front protection-glass and NOT the actual Plasma Panel thats cracked...?

IF the Plasma Panel has suffered a crack/damage, then this will be causing your problem.

SOS-7 is related to floating-supplies and Buffer circuits as I recall....

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

In your first line, you say--

Slightly cracked Panel ( 2 inch 'X' shaped crack on the left bottom side) got hit with a golf ball...........

Can you confirm, that its just the front protection-glass and NOT the actual Plasma Panel thats cracked...?

IF the Plasma Panel has suffered a crack/damage, then this will be causing your problem.

SOS-7 is related to floating-supplies and Buffer circuits as I recall....

I had a look in the US model XT50 and it did not show a front protection panel in the PDP removal procedure. Do you know if these have one? I know Panasonic started deleting these in the higher end panels from about 2010.

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Pin 1 to 2 and pin 2 to 3 is 295 ohms. Pin 1 to 3 is dead short on Daf30a.
I have not yet removed the panel from the cabinet/bezel. But when I look at the panel edges it seems like there is no separate glass between panel and the bezel. The TV specs mention the panel as VIERA Tough Panel .. I don't know what it means.
Tw2005, I will test as you mentioned. Is there any test I can do on the panel to specifically know if it has shorted electrodes.

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Pin 1 to 2 and pin 2 to 3 is 295 ohms. Pin 1 to 3 is dead short on Daf30a.
I have not yet removed the panel from the cabinet/bezel. But when I look at the panel edges it seems like there is no separate glass between panel and the bezel. The TV specs mention the panel as VIERA Tough Panel .. I don't know what it means.
Tw2005, I will test as you mentioned. Is there any test I can do on the panel to specifically know if it has shorted electrodes.

I have not idea what the correct resistance is on that diode, and no I doubt you can check the panel like that. tough panel, well be interesting to know if it can crack and preserve the panel. the fact you still see a flash of white has me curious.

7 blink shutdown is going to be either Sn or panel or both. have never been in this situation

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

I was looking at this. https://www.youtube.com/watch?v=aXEu04k_YMM

Your kid must have a good arm to have cracked it then. Must have been a big hit.

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Now I realise ... The golf ball came from behind and hit the tv. Had it hit me on the head I would have been in the emergency care ( a more expensive case).

The guy in the video says the panel can withstand 4 joules ( I don't know how to relate that figure to impact ). I think it was one of the best timing shot from my kid with a short club and it may also be that the running panel was hot enough to lose its claimed toughness to impact force. The golf ball because of its smaller dimension may have Exerted more force at the smaller point of impact. Never new that golf ball was so hard.

I will test if there is anything short in the panel ribbon cables and report back.

[tom66]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

These newer panels don't have the Tough Panel, the glass is very easy to damage (though not as easy as an LCD.)

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Specs of TH-P42XT50 from panasonic website.

http://www.panasonic.com/sg/consumer...t50.specs.html

Online retailers selling the same model here in India
http://m.snapdeal.com/product/panaso...t50d-hd/609340

http://www.gadgetsguru.in/panasonic-...dia-15945.aspx

I never bothered too much with the specifications at the time of purchase but I think I may be lucky this time to have bought a viera tough panel tv unknowingly. A bit more hope that the panel may be alive somehow.

[Alastair E]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

Nah--If the PANEL IS CRACKED in ANY way, shape or form, Its Finished! Curtains, Shuffled off this mortal-coil, Gone to meet its maker, Its an Ex Parrot OOps, Plasma
This TV is deceased.

Time to change your preferred sport--Maybe to jogging. No danger to TV screens from that!

It is Highly unlikely you'll find any shorts on its electrodes, its a case of arc under a high-voltages the panel runs at normally will then kill other items on the SUS boards/Buffers.

[Chaks]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

SRV VFO to all the pins of panel connectors are open. I checked this thrice to be sure.


Tw2005: "I was thinking , disconnect the panel ribbons from both the SS and the SN, but have the SN connected as normal, fire it up and see if it stays on."

When I did this ... The panel lits up for 2 seconds ... No hiss sound from the speakers ... The power led blinks 7 times again. Back to the beginning.

When I disconnect the SN board ... The panel lits up white for 5 seconds along with hiss sound from the speakers ... And blinks 6 times ( six times ). I have also noticed that a Red LED below the optical-audio-out board connector on the 'A' Board lit up for about 5 seconds. The red led lit up as long as the white screen was displayed. This I did not notice when I did the testing earlier.

It seems that the SN board is faulty. The SN board costs about $ 100 here in India. If the SN board is repaired then it is ok ... otherwise it becomes a $275 panel + $100 SN board = $ 375 ... For the parts alone.

[tw2005]

Re: Panasonic Plasma TV TH-P42XT50D PCB - 7 blinks

SRV VFO to all the pins of panel connectors are open. I checked this thrice to be sure.


Tw2005: "I was thinking , disconnect the panel ribbons from both the SS and the SN, but have the SN connected as normal, fire it up and see if it stays on."

When I did this ... The panel lits up for 2 seconds ... No hiss sound from the speakers ... The power led blinks 7 times again. Back to the beginning.

When I disconnect the SN board ... The panel lits up white for 5 seconds along with hiss sound from the speakers ... And blinks 6 times ( six times ). I have also noticed that a Red LED below the optical-audio-out board connector on the 'A' Board lit up for about 5 seconds. The red led lit up as long as the white screen was displayed. This I did not notice when I did the testing earlier.

It seems that the SN board is faulty. The SN board costs about $ 100 here in India. If the SN board is repaired then it is ok ... otherwise it becomes a $275 panel + $100 SN board = $ 375 ... For the parts alone.

actually just realised C buffers are still powered, maybe P35 needs disconecting to remove power because the panel should not light up.