1/4 of display missing on Samsung PS-50A457P1D

[bigted01]

Hi All!
I have inherited a PS-50A457P1D, and have a small problem!

When I switched it on, it seemed fine, then a series of verticle white lines with a pink line in the middle appeared, just left of centre.

Did a bit of research, and found it could be a loose cable. I carefuly reseated all the ribbon cables, and fired her up. Lines all gone! BUT! Now, the right hand quarter of the screen no longer works. everything else seems fine. By disconnecting the ribbon cables that leads down to the boards at the bottom, one at a time, then powering up, it shows that the screen itself is getting power on that side and lighting up, it just doesn't get the picture.

As I understand it these lower boards are E & F buffer boards , but I dont fully understand if this is what's at fault. Would simply replacing these clear the fault? If so, how do I go about it as I can't find any info on this on the web.

Any Help Greatfully Recieved!

[sordids999]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Posting some pictures with the back off showing clear pictures of the boards will help you more with fixing your problem

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

DUH ! Should have thought of that!

I have put one up of the front and Rear (with panel off!) and a couple of the other boards. Also the makers panel on the rear panel of the set.

[freakaftr8]

Re: 1/4 of display missing on Samsung PS-50A457P1D

I would say if the panel is priming on that side you probably have a bad control board or a really bad connection on the ribbon cable. Does a ribbon cable look marred on the connections or torn in any way?

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Ok, following what freakaftr8 suggested, I have re-examined all the ribbon cables I can get to. All the cables seem ok and undamaged. However, as you will see in the one picture attached, there seems to be some pins damaged on the left hand end of the socket of one cable.
This is the cable that connects the Logic buffer F card to the rest. I compared it to the one on the E board, and as you can see in the pic ( look close, sorry it is a little blurred!) there seem to be three small pins missing. I carefuly removed the cable and got a torch and mag. glass in there. The lower part of the pins are there, it just seems to be the part that protrudes through the brown clamp that is missing.

Worth noting also that this board is the F board which if you are looking from the screen side is the left hand board. but the missing piece of screen is on the right. (E Board).

As I said before, bit of a newb to this so I am trying to be as clear as possible, not teach my granny to suck eggs !

Thanks Guys!

[Alastair E]

Re: 1/4 of display missing on Samsung PS-50A457P1D

The fault will line up with the image problem on the screen.

So--If that plug/ribbon is on the Other side to the displayed fault--It Isnt the problem.

Check the ribbons/COF Chips immediately Under the displayed faulty image area on the screen--Thats where the fault will be.

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Thats what I thought Alistair. The E buffer board was my guess. How to get to it is the next thing! The conection at the top seems ok, but I believe there are a series of cables at the bottom. Didn't touch these originaly as they are hard to get to. Oh well, out with the screwdriver again!

Is there any way of testing it without pulling it all to bits?

Cheers

[mmartell]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Be careful not to plug/unplug these E/F buffer connectors when power is applied or even off while the main caps are still charged or you can destroy the panel.

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

I haven't done, but you've scared me now! Do you mean the boards or the whole TV!

[mmartell]

Re: 1/4 of display missing on Samsung PS-50A457P1D

I mean specifically the connectors to the E and F buffer boards you are working on but it's probably good advice all around.

Hey freak was it you that made this "discovery" the hard way ?

[freakaftr8]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Yes I made that mistake along with others. Lol. No d
Good.

If you play with the panel connections for e buffer to panel assembly itself you will surely destroy it. If you have played with the white ribbons that go from the control board to the e buffers you can short out the control board causing a symptom of like what you see. However playing with the white ribbons while powered up will not harm the panel itself in most cases.

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

I could do with some instructions on getting to the E & F boards, Have had a squint, but it looks awfuly tricky. Anyone know where I can get service instructions or service manual for this set?

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Freak, do you think it more likely I have a damaged control board or something on the buffers. Following earlier posts, and a bit more digging, I have a horrible feeling I have shorted something by not leaving the set long enough to let the caps discharge. I have located both parts, and to be fair the control board looks a hell of a lot easier to change!

[freakaftr8]

Re: 1/4 of display missing on Samsung PS-50A457P1D

The control board is worth a shot. Only because you mentioned that the panel is priming in the dead area. If it lights up in the dead area I believe there is hope.

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

I have located a board, it is the same PCB No, but mine is REV No R2.0, and the one I have found is REV No R2.1 , will this be ok, or does it need to be exactly the same.

The seller says it is from a PS50A456P2D set, but I assume if the PCB no's match it should be ok?

Sorry to appear a bit thick!

[sordids999]

Re: 1/4 of display missing on Samsung PS-50A457P1D

would it not be worth trying test patterns on the control board freakaftr8 to see if that side that seems dead works unless im wrong ?

[freakaftr8]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Good call sordis999! OK bigted01 on your old control board you should see a block of jumper pins. First disconnect the LVDS cable going from main board to control board. Then after that's done first find a jumper or anything you can short pins 3 and 4 together and power up TV. what you should see is a random picture of different colors coming up flashing between red green blue white and others. Is the whole screen there?

[bigted01]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Right Then. Before I go ahead and blow everything to bits!

Have attached a couple of pics to be sure I am looking at the correct bits!

Thanks for being patient guys!

[tom66]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Looks good to me... assuming "cable to main" means that flat white one going between the two boards all is good to try it.

[sordids999]

Re: 1/4 of display missing on Samsung PS-50A457P1D

Correct you should hopefully get test patterns