2008/9 Samsung LN55A950 Displaying Horizontal Lines

[Badsammy]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It would be from the backside, with the ribbon closer to the main board. That was the ribbon causing the horizontal lines on my set.

As for cleaning, all I used was a microfiber cloth and a good hard rub on both ends of the ribbon. Air was used on the connectors, which had plenty of dust.

[TallCoolOne]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

So I tried Badsammy's approach, no luck for me. I swapped the far right and left ribbon cables around and cleaned all four of them with a microfiber cloth, still no change. If I disconnect the two right side cables and fire it up, the left half of the screen is a not very uniform white/grayish white, but with NO lines. Could that be an indication that it is not the panel itself?

[Glitcher]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Actually that's a good indication that the panel is probably bad. One side of the panel has a bad driver that is loading down the tcon when they are all plugged in.

[TallCoolOne]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Actually that's a good indication that the panel is probably bad. One side of the panel has a bad driver that is loading down the tcon when they are all plugged in.

Interesting, so in that case, if I pull the left 2 ribbons instead I should then get only the left half of the picture showing and white on the right with no lines right? The lines are always on the left right now.

I put the case back on right now so that's not an easy test...

Which capacitors are people seeing that are bulging? They all look fine to me but I didn't remove the cover from the tcon board to look at the ones on it..

[freakaftr8]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Feel for one of the IC's to be hot on the ribbon cables on the panel

[TallCoolOne]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Feel for one of the IC's to be hot on the ribbon cables on the panel

which IC's, on the tcon? not sure what you mean by IC on the ribbon cable on the panel...

i'll pop off the back again..

[tibimakai]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Here is an example:

[TallCoolOne]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

I see, thanks for the image. I am looking around but don't see any with black marks nor anything overly warm...

[killjoy2013]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Here's the results of testing Badsammy's suggestion on my unit. It's mostly bad news, but good news in that I think this confirms my earlier conclusion. I'd ask the experts to weigh in please. I'll try and keep this short & to the point.

Here's the 4 flat ribbon cables that connect between the Tconn board and LCD panel for reference. Both ends are removable, and the connector on the panel side is fairly well recessed into the metal frame.


Finding #1: When I swapped the 2 inside cables with each other, and 2 outside cables with each other (post cleaning), upon power up, the TV presented the exact same issues and picture since post #1 of this thread. NO CHANGES by swapping left cables to the right and vice versa.

Finding #2: When looking at the front the TV, I unhooked the 2 right side ribbon cables. Upon power up, the left side of the screen (that was still receiving signal) displayed a funky red, blue and green set of vertical patterns. The right side (unhooked side) was just greyish white, and no horizontal lines.



Finding #3: Powered down, reconnected the 2 right side cables, and unhooked the 2 left side. Then powered up. Result - The right side picture is perfect, and left side greyish white without any horizontal lines.


Finding #4: The results of #3 proved to me that those 2 ribbon cables on the right side were working OK. So, I powered down, and moved them both to the other (left) side, leaving the right unhooked. This is basically the same test as #2 but with 2 known-good ribbon cables. Unfortunately, same result as #2 - red, blue and green pattern on the left.


So, given these results & the fact that the Tconn board has already been replaced, I'm speculating that this confirms that I have some type of electronics failure on the left-side of the display panel, downstream of the Tconn -- which is basically unrepairable. Thoughts? I'd really like to try one final test -- hooking the 2 right side Tconn outputs to the 2 left side panel inputs, just to confirm that the issue remains, and I don't just have 2 faulty Tconn boards that are bad on that left side. Unfortunately, those ribbon cables are so short, I'm going to have to unmount the Tconn and hold the board up temporarily to be able to do this. Can one of the gurus please confirm that if I want to do this last test, which Tconn right-side output cable should connect to which of the 2 LCD left side inputs? e.g. are the 4 Tconn outputs R1-R2__L1-L2, or R1-R2__L2-L1?

[newtothis]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Dead Panel

With what has been changed and the the removal of the cables to the left of the panel it is showing that the driver board is dead.

Time to break it for parts I'm afraid

[TallCoolOne]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

killjoy, thanks for reporting back your results. I got the exact same result as you in step #3 (white on left, good picture on right, no lines). I also tried swapping the cables in various positions to no avail. I didn't try only the right cables unhooked but i'm guessing mine will do the exact same thing (color patterns on left of screen).

oh well, it was worth the effort, thanks everyone for the suggestions and killjoy for experimenting so much...time to buy a 4K set

[killjoy2013]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Yup, no problem.

Tonight, I pulled out the replacement Tconn board and put the OEM back, retested the same work from last night -- same results, same red/green/blue pattern on the left side when the right input is unhooked.

I also unscrewed the Tconn from the panel, shifted it over a few inches and wired the 2 right side Tconn outputs to the left side LCD inputs, holding the Tconn board in my hand while powering up to making sure it didn't short against the case... and it wasn't happy. Heard some faint clicking from what I believe is the LCD driver - not sure - but I'm guessing the ribbon cable pairs are flipped flopped left vs. right side, and there's no way to cross the ribbons to test since they're too short.

[mmartell]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It wasn't happy because it is SUPPOSED to be grounded, and it is when you mount it and put the screws through it.

[newtothis]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Can definitely say the panel is dead I'm afraid

[mmartell]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

If I were you I would tear that set down and get to the tabs (especially if you are going to part it out anyway).

You've got nothing to lose.

[newtothis]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It wont be the tab bonds in this case... it will be the driver board as it is affecting the entire side

[killjoy2013]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It wasn't happy because it is SUPPOSED to be grounded, and it is when you mount it and put the screws through it.

Understood, but there's no obvious traces on the Tconn board to the screw holes for grounding (or, at least, I don't see any), and with the 4 ribbon cables hooked up the correct way and board unmounted, the TV displayed the same picture as when it was fully mounted, 'grounded' and secured. I would hazard a guess that adequate grounding was being provided by the signal input cable from the dimmer/main board.

It wont be the tab bonds in this case... it will be the driver board as it is affecting the entire side

Are those driver boards a serviceable part? I'm a novice, but I thought only a $50k tab bonding machine could re-fasten the tabs?

Think this is getting to the point of calling it dead, pulling the boards and putting them on ebay, and move on with life... but you can tell me I'm wrong.

[newtothis]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

The drivers are part of the panel and cannot be repaired, sometime stab bonds can be "wedged" into place and create the contacts but it seldom works, i had a single vertical line down my panel once and tried to "wedge" it... killed the bond completely!

The set is dead sorry to say

[mmartell]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

The reason I'm an advocate for it is because I fixed one myself.

However you raise a good point in regards to it being the whole side of the panel as mine was only a couple of inches wide, the area responsible by the tab in question.

Here's an idea. Turn it sideways and use the working half as an awesome computer monitor Damn shame to let a nice set die a death that way...

[tibimakai]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

I see, thanks for the image. I am looking around but don't see any with black marks nor anything overly warm...

That picture is taken after the panel is taken apart. Front plastic bezel off, metal frame of the panel removed. There are a lot of these ribbon cables. Those have problems, not the T-con ones.