Prima (Samsung) 42" Plasma no Pic/Sound

[kevinw]

Hello anyone who cares! This is my first post here....

I have a Prima 42" plasma TV (Samsung display and boards), with no picture or sound. Model PH42T7.

The PS Board is a LJ44-00092C
Plus 3 other Samsung boards:
LJ41-02758A
LJ41-02759A
LJ92-01270A

and 2 Pixelworks boards:
782-PH42T8-690B
782-PS42T9-550B

The standby light comes on when the TV is plugged in, and both the remote and the front panel will switch the set "on" (the red led goes green) followed by the relay "clicking" on the PS board. 2 or 3 seconds later, there's a slight "click" in the speakers, but that's all the sound I get...

I've checked voltages on the PS and they all fall within the parameters printed on the board itself.

With an HDMI input from a DVD player, I've tried cycling the "Input" button but get no sound at all.

Interestingly, pushing buttons on the remote activates up to a dozen pixels of various colors, but that's all the picture I can get.

How many new boards do you guys think it will take to ressurrect this 5 year old boat anchor?

Thanks in advance for any and all suggestions / solutions.

[PlainBill]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Hello anyone who cares! This is my first post here....

I have a Prima 42" plasma TV (Samsung display and boards), with no picture or sound. Model PH42T7.

The PS Board is a LJ44-00092C
Plus 3 other Samsung boards:
LJ41-02758A
LJ41-02759A
LJ92-01270A

and 2 Pixelworks boards:
782-PH42T8-690B
782-PS42T9-550B

The standby light comes on when the TV is plugged in, and both the remote and the front panel will switch the set "on" (the red led goes green) followed by the relay "clicking" on the PS board. 2 or 3 seconds later, there's a slight "click" in the speakers, but that's all the sound I get...

I've checked voltages on the PS and they all fall within the parameters printed on the board itself.

With an HDMI input from a DVD player, I've tried cycling the "Input" button but get no sound at all.

Interestingly, pushing buttons on the remote activates up to a dozen pixels of various colors, but that's all the picture I can get.

How many new boards do you guys think it will take to ressurrect this 5 year old boat anchor?

Thanks in advance for any and all suggestions / solutions.

I can't find any reference for the 782-PH42T8-690B, but the 782-PS42T9-550B is the main signal board. That handles all signal inputs and passes sound and video to the audio amp and main control board respectively. The odds are very good that one is responsible. As an interesting exercise, you could try hooking up an analog source and repeat the exercise of cycling the input button. If that works, you have established you are dealing with a problem with the main signal board.

There are two of them available on eBay for just under $100. This Samsung plasma panel is noted for a high failure rate of the Y-buffers. More significantly, a failure of a Y-Buffer will also take out the Y-Sustain card. Replacing those gets expensive. I suggest downloading the service manual for the S42AX-YD02 plasma panel (it's available on Scribd). By placing a jumper on the proper point on the LJ92-01270A you can put the panel into test mode. If it lights up, you have a good panel, buffers, sustain card, etc.

PlainBill

[pelota]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

I have the same TV in a semi working condition. You might want to check out http://blog.coppelltvrepair.com/2010...er-boards.html , it shows how to check if the buffers are burned. If you junk it I might be interested in a part or 2.

[pelota]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

I have the service manual for the TV, not the panel, let me know if you want it. It has 9 pages of schematics of the digital analog board.

[kevinw]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Thanks to PlainBill and Pelota for your quick responses and suggestions.

I checked the Y-buffer boards per the Coppell website, and they both appear OK (i.e. high resistance in both directions at the power connectors).

I also tried an analog input to the main signal board from my DVD player, but again, no sounds to be heard.

I D/L the S42AX-YD01 manual from scribd but the boards it describes do not match the ones I have, (i.e. no LED's on my PS and no DIP switches on my Logic Board) so I can't apply the tests per that manual....

At this point I believe the main signal board is dud, so I'll hop on over to eBay and spend $100 (plus shipping) on this thing.

Thanks again for your help. I'll let you know how it turns out!

[PlainBill]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Whoops!!! One warning - the boards on eBay are from a Polaroid TV. Ordinarily I'd say no big deal, but the Main Signal board usually contains the firmware. At best it would say 'Polaroid' in the main menu. At worst, it wouldn't recognize the other card.

PlainBill

[kevinw]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Well, let's hope for the best then! I don't care if the firmware decides that the TV is Polaroid, so that's OK. I just hope the boards recognize each other, since they're the same revision letter?

[kevinw]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Here's an update for the benefit of others who might be reading this thread and who have this (or a similar) TV:

I switched the 782-PH42T8-690B and 782-PS42T9-550B video boards, but I still had the same problem. ($100 experiment there)

Changing out the LJ92-01270A did the trick, for only $30, and I now have a working Plasma TV again!

And: If ever those two video input/controller boards fail, I'll be ready!


As a final note: I had no sound output through this whole process because my stupid Samsung DVD player does not output sound on the HDMI line by default! So audio was there the whole time, but ironically, I needed video to select it....

[kevtec1]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

hello could you please forward me a copy of the manual? thanks,m,,cheerz,...Kevin mcdonald

[Bartdude]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

I have the service manual for the TV, not the panel, let me know if you want it. It has 9 pages of schematics of the digital analog board.

Hi Pelota,

Could you please send me the service manual for the Prima 42" Plasma? Much appreciated, thanks!

[yeorgos]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

[QUOTE=kevinw;129511]Hello anyone who cares! This is my first post here....

I have a Prima 42" plasma TV (Samsung display and boards), with no picture or sound. Model PH42T7.

The PS Board is a LJ44-00092C
Plus 3 other Samsung boards:
LJ41-02758A
LJ41-02759A
LJ92-01270A

The standby light comes on when the TV is plugged in, and both the remote and the front panel will switch the set "on" (the red led goes green) followed by the relay "clicking" on the PS board. 2 or 3 seconds later, there's a slight "click" in the speakers, but that's all the sound I get...

With an HDMI input from a DVD player, I've tried cycling the "Input" button but get no sound at all.


Hi Kevinw
I am trying to fix a similar problem on the same model, and would like to clarify one of the symptoms you experienced.
When you say no picture and no audio, does that mean that you were not able to see the input menu when you were cycling through for your dvd player? This screen does absolutely nothing so far, but I have yet to do the test mode suggested by PlainBill.

Thanks for going through with the fix btw, it gives me hope

[ih8lag]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

Since there are only 2 active threads on this model. I am going to post here.

With my ph-42t7 it has been working great for almost 4 years and all of a sudden starting this week periodically the bottom half of the screen had no display when turned on but after a minute or so it comes on. As well once I believe that I had no sound and picture I cannot confirm this as my STB will go into a standby mode.

[ronklo]

Re: Prima (Samsung) 42" Plasma no Pic/Sound

I have the service manual for the TV, not the panel, let me know if you want it. It has 9 pages of schematics of the digital analog board.

Could you send me a copy of the manual? I have 2 of these TV's with the same issue. Turns on/off, but no video or audio (other than a small noise at power up). Remote turns TV on & off but no other buttons on the TV or remote do anything. It does feed a video signal from cable or A/V input to the A/V out but no sound there either.

Thanks,