Samsung 3D Plasma, Few Lines on Screen Please Help!

[graham01]

Hello all,

My TV is a Samsung PS50C7000, a slim 3D model. about 10 inches from the left side of the screen there is a vertical line 1-2 pixels in width in which all the pixels in it flicker a different colour and it doesn't seem to be related to the picture, it is very bright and annoying. There is also 2 vertical green lines to the right of the screen that are 1 pixel width and very faint, sometimes can't be seen.

I also think the whole picture has a slight noise on it, it cant be seen when playing games, but it can be seen on the boxes saying "HDMI1" and "No Signal" etc..

I don't know anything about Plasma TV's, but I think I can spot an X-sus and Y-sus.

I THINK - looking at the back of the TV, the Y-sus is located at the left with ribbon cables down the left hand side, the X-sus is on the right with ribbon cables down the right hand side, the logic/main controller is underneath the PSU in the middle (don't know the name of it but it connects to the x-sus, y-sus, tuner board and some boards along the bottom I don't know what they are)

To me however, I would assume the boards connected with ribbons at the bottom of the screen control the Y lines and the boards at the side control the X lines.

I disconnect the boards located at the bottom of the screen and powered it up, however the big white colourful line was still there! And I am even more confused because that board was making a buzzing noise when ever it was moved but there was no cables plugged into it!

So I'm not going to fiddle on with anything else because I am bound to damage something else, can anyone please help me here? I would really appreciate it!

Regards

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

The Y-sustain controls the rows. Surprisingly, the X-sustain doesn't control the columns, but just the picture erase, brightness and precharge. The X-sustain is sometimes called the X-main by Samsung, SS board by Panasonic and Z-sustain by LG. Y-sustain is called Y-sustain by Samsung & LG, and SC by Panasonic.

The sustain boards in this case are unlikely to be at fault - leave them alone. Buzzing is typical from the sustain boards when the panel ribbons are disconnected.

The random noise is typical of plasma TVs. Each pixel can only occupy on or off states (some might occupy multiple states - but they are newer technologies), so they are flashed on and off rapidly to create the required colour, and many next to each other add to the effect. When close up it looks poor, but further away it works quite well. Look up dithering.

It sounds like an X-buffer problem (the X-buffer does actually control the columns... and at least its naming is consistent.) However, in rare cases, it can be the panel itself, in which case the repair is uneconomical (panel costs around 50-75% the price of a new TV!) I know most Panasonic TVs which develop vertical lines are unrepairable (they put the driver ICs directly on the panel substrate - go figure - if they go wrong [which sometimes happens esp. due to the high voltages these panels use, and the high temperatures they operate at] the panel is unrepairable), but I'm not sure about Samsung - some models might put them on the X-buffer boards which are cheap, others might not.

Q: Did the problems develop simultaneously or have they developed over time?

Can you post a pic of the X-buffer boards? They're on the bottom of the TV and connect to the panel.

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Thank you so much for your reply!

It sounds like I have been unfortunate with this model then, the X-buffers are fixed to the ribbons on the screen..

This problem just occurred, but when I took it apart I was surprised to see the speaker screw mounts under the panel have snapped off, one of these mounts being directly under ribbon connecting to the screen where the line is.. I'm not sure how or when this happened, but the tv must have received some hefty impact to cause this.. looking at the geometry of the TV inside, it looks like you could drop this TV off a building and the only thing that shouldn't really break is those speaker screw mounts! It just doesn't make any sense to me because all the other screw mounts and the rest of the case is in pristine unmarked condition!


Anyway, I am guessing it is that X-buffer board (there are 2) or the ribbon that has some form of damage.. I took the entire screen out though and looked very closely around the edges of the panel there appears to be absolutely no damage to anything!

If you would still like a picture of the board I can take one later.

Thanks again for your help..

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Thank you so much for your reply!

It sounds like I have been unfortunate with this model then, the X-buffers are fixed to the ribbons on the screen..

This problem just occurred, but when I took it apart I was surprised to see the speaker screw mounts under the panel have snapped off, one of these mounts being directly under ribbon connecting to the screen where the line is.. I'm not sure how or when this happened, but the tv must have received some hefty impact to cause this.. looking at the geometry of the TV inside, it looks like you could drop this TV off a building and the only thing that shouldn't really break is those speaker screw mounts! It just doesn't make any sense to me because all the other screw mounts and the rest of the case is in pristine unmarked condition!


Anyway, I am guessing it is that X-buffer board (there are 2) or the ribbon that has some form of damage.. I took the entire screen out though and looked very closely around the edges of the panel there appears to be absolutely no damage to anything!

If you would still like a picture of the board I can take one later.

Thanks again for your help..

A picture would be very helpful of your buffer boards, it may be that they are replaceable.

As far as Samsung TVs go, their quality control is less than superb. I've had a plasma which had an audio jack cut out on the rear panel too small than the others, preventing proper insertion of a cable, luckily it wasn't difficult to fix. So it wouldn't surprise me if the damage you noticed happened at the factory and they just put it together hoping it would be okay.

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Hi Tom, thanks again..

The Problem;



Inside the TV;



Here, the red arrow shows where the vertical line is, the red circles are where screw mounts have snapped;



Regards

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Also there is a metal guard that I removed for the pictures and it fits over the ribbons, it has been undamaged so I don't think there has been any physical contact to the ribbons or the buffers during the damage to the screw mounts.

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Darn it, looks like you have a panel where the buffers are bonded straight to the FFCs (flat flex cables) and the buffer ICs are on the panel's FFCs. That's got to be the worst design I've seen yet. With an insulated screwdriver, try applying pressure to the FFCs to see if the picture clears. Any repair however will eventually require a new panel. Sorry!

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Hi Tom, thanks, well that massively sucks... yea I have tried playing around applying pressure here and there but there's not even a flicker of change..

Any nice panel suppliers out there that wouldn't mind being a bit generous?? lol

Regards

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Hi Tom, thanks, well that massively sucks... yea I have tried playing around applying pressure here and there but there's not even a flicker of change..

Any nice panel suppliers out there that wouldn't mind being a bit generous?? lol

Regards

On the back of the TV there is a model number for the panel in question.

I have seen some sellers selling the panels for around $100 removed from faulty TVs so you could get lucky but most faulty TVs get repaired, especially a slim 3D plasma. How old is the TV anyway?

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Hi again, wow that is cheap! I thought they would be near enough the price of a new TV! I am in the UK though, and I THINK the panel model is 850FH-YB07.

Regards

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

Hi again, wow that is cheap! I thought they would be near enough the price of a new TV! I am in the UK though, and I THINK the panel model is 850FH-YB07.

Regards

I'm in the UK too, I just tend to revert to $$ automatically for some reason!

Unfortunately no luck finding a panel for that on eBay... As I said $100 would be lucky. Saw a 42" full HD LCD panel (just the panel) for £80. You might do well selling the TV faulty as is on eBay to someone who can source the panel or strip it for parts.

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

why would you ever want to revert to $ haha!

Yea I tried ebay, no worries.. I think you are right about flogging it on ebay how it is, I will just do that!

Thanks for all your help!

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

i have just been playing around with the FFC at that line and if I apply pressure on a certain part I can make the line change from white to purple! lol

[tom66]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

i have just been playing around with the FFC at that line and if I apply pressure on a certain part I can make the line change from white to purple! lol

Applying some more pressure may fix the problem, if only temporarily.

[graham01]

Re: Samsung 3D Plasma, Few Lines on Screen Please Help!

yea, I applied quite a lot of pressure and was quite over the moon when the line disappeared, but when i put an image on the screen I discovered it only went black lol.. i put the tv back together anyway and I can't be bothered to faff on with it anymore