panasonic tx-p55vt30 and tx-p55st60 problems.

[dj01fad]

Hello all.

I have a chance to get for a good price a tx-p55vt30 and a tx-p55st60 plasma TV's. the problem is:
- on the 55vt30 - it starts and remains on black screen. it has audio and changes programs from the remote. the seller says that in a dark room you can see that the screen is powered
- on the 55st60 - on start relay clicks, or rarely it starts. it displays the image, but is not responding to the remote, and you cannot change the program. the front led is completely off...

it's ok to buy them? what are the chances to have a bad panel on the vt30? on the st60 I know that is possible to have an A-board problem or around it (the front pcb with the remote sensor and led maybe)

[tw2005]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

Tough to say, I'm thinking A-board on the st60. the VT30, a bit sus on that. I think you will have to have a look and judge yourself. Could also be A board if it's on, no fault codes and has sound.

Same seller both TVs?

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

yes, same seller. the price is 100 Euro for each. he doesn't have spare parts, but another friend has a whole 55vt30 with a broken screen... for the st60 I do not have spare parts, but I'll try to heat the board; it worked for me on 2 A-boards from gt30 TV's.
he also has a LG 50PA6500 with y-sus board broken on 65 Euro.
I think I'll buy all of them, and hope I'll fix at least one. hahhaha

[tw2005]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

In my currency that seems a lot of money. I get suspicious, if they're into fixing but ditching them. have they damaged anything inside or tampered to hide a fault.

I've had a couple where power supplies had been disconnected or tampered to hide faults.

I think important thing with the GT30 is the panel ok? Hopefully you can tell if it's being powered or not. It could be possible to disconect enough so the TV turned on and produced sound , no image.

Good luck with it.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

100 EUR = 150 AUD; You think It's expensive for this price?
I know this man, I trust him, and I know he did not anything wrong to these sets; he is not a repair man, and this is just a hobby for him (like in my case). he told me that on the vt30 the screen is powered, and you can see it if it's dark in the room. I'll go for them on saturday, and I'll take with me an A board for the VT30. He will let me try whatever I want, so I guess it's OK.

[tw2005]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

100 EUR = 150 AUD; You think It's expensive for this price?
I know this man, I trust him, and I know he did not anything wrong to these sets; he is not a repair man, and this is just a hobby for him (like in my case). he told me that on the vt30 the screen is powered, and you can see it if it's dark in the room. I'll go for them on saturday, and I'll take with me an A board for the VT30. He will let me try whatever I want, so I guess it's OK.

Well that's different then. yeah, for here broken too much but then you have to be lightning quick to find one they get snapped real quick and often $50 -100 AUD or free sometimes.

[kc8adu]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

no pic but glow in dark room means sus,buffers,power supply ok.
main board failure.
i have reflowed a few of these myself.
and installed a better heatsink on the asic.
could be the problem on both sets.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

I reflowed some myself too, and they work fine with a laptop cooler installed...
I'll get them tomorrow. wish me luck

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

yes, same seller. the price is 100 Euro for each. he doesn't have spare parts, but another friend has a whole 55vt30 with a broken screen... for the st60 I do not have spare parts, but I'll try to heat the board; it worked for me on 2 A-boards from gt30 TV's.
he also has a LG 50PA6500 with y-sus board broken on 65 Euro.
I think I'll buy all of them, and hope I'll fix at least one. hahhaha

Don't get the PA6500, probably a bad panel...

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

Don't get the PA6500, probably a bad panel...

he said that after disconnecting the supply from y-sus the TV came alive with sound.
if you say that... then I won't get it...
Thanks.

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

he said that after disconnecting the supply from y-sus the TV came alive with sound.
if you say that... then I won't get it...
Thanks.

There's a common issue on these where the panel kills the upper buffer, well technically it's the screw mount for the case rubbing into the ribbon cables but it's all the same as you can't change those.
I'm not sure if it kills the Y sus as well, might do, might not, so could be another fault, just be aware there's a chance it's the panel.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

I can take a look inside on it. if it's the rebbon I should see something wrong... If I won't be able to see anything wrong, it still can be the panel?

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

I can take a look inside on it. if it's the rebbon I should see something wrong... If I won't be able to see anything wrong, it still can be the panel?

It is really hard to see the damage but the top left ribbon from the top buffer board tends to get a slight kink in it which is the death of the panel.
It probably isn't the panel if this isn't the case, excepting the obvious cases of stuck vertical lines, which LG's are somewhat known for, but reasonably rare.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

OK, it's a no-go. just the pannys should be enough )

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

Hello there,
The vt30 shows the same dark screen with my good A board. The screen is powered, and when I turn it off from remote I can see that the screen comes a little lighter. No buzz sound.
Any ideas? It's possible to have a sc-board issue?

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

Do you have an oscilloscope?

Check Vad, Vscn, and Vsus

Approx -200V, 150V and 210V each.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

At that moment I was at the seller's place; I took for me only the 55ST60, because I am sure it's just the A board: sometimes it comes alive and displays picture, but doesn't respond to any command, from the panel or remote. I took also the 55VT30, but for a friend, not to keep it. I measured those with a multimeter and the values were near what you say with one exception. If I remember correctly, Vsus vas 209, Vad and Vscn were 204 and 180, or some like this. I can check again tomorrow because the TV will stay a week or two at my place until my friend comes to get it... it's strange because I remember that when I was testing a 50GT30, and forgot to connect the A board to the SS board, the TV started on solid green LED, but and I received a beautiful black and dark screen. same case here, but the little led on the SS is now green (55vt30), and on my test (50gt30) it was not. I hope it's not the panel, and I cannot see how it can be...

another question: I think I might have an A board from a 42ST60. do you think it's ok to use in a 55 set? I know that this is not possible at 30 series...

if possible please edit post #3: in the end the VT30 was 150E and the ST60 was 220E. it was a misunderstanding with the price... the LG 50PA6500 was the one at 100E, but it was not for sale anymore (strange thing right?).

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

Don't use the wrong panel size board, could cause damage.

A plasma panel works by AC discharge. You will not get any light out from it if the A board is not sending the control signals to the SC/SS boards. In other words, it won't glow on its own.

[dj01fad]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

A plasma panel works by AC discharge. You will not get any light out from it if the A board is not sending the control signals to the SC/SS boards. In other words, it won't glow on its own.

Yes, but it's hard for me to belive that it's the panel... In 99% cases a bad panel has another behaviour.

[tom66]

Re: panasonic tx-p55vt30 and tx-p55st60 problems.

I didn't say it was the panel. I said it could be something else, including a faulty A board. But a lack of glow could mean many things. It's hard to say. Panasonic sets (and plasmas in general) are hard to diagnose without an oscilloscope.