2008/9 Samsung LN55A950 Displaying Horizontal Lines

[killjoy2013]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Anyone have anything new to add? Otherwise, I'm going to starting stripping my TV tonight -- no going back.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Have same set - vertical lines. anybody seem this ??? going to fiddle with wires. Is this problem similiar to sony bravia distorted screen (buffer tabs). Has anybody tried pushing on the tabs on this set ????

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

pics

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

90% that's a bad panel, small chance of a bad VGH/VGL circuit on the t-con causing issues.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

reconnected all connectors - now screen show this on power up. OSD does nothing. can this be a buffer tab "fix" ?? flexing tv does nothing

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

after a minute = the screen is completely white. menu does nothing, TCON board heat sink is cold - think TCON board is bad

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It's screaming panel to me, you can try checking VGH and VGL on T-con if you want, but I suspect the panel is bad.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

when u say panel bad - is this a buffer tab "fix" like sony bravias ???
guess I have nothing to lose by playing with buffer tabs. I've had good success with sony bravia repairs.

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Possibly but it seems more likely to me that something is actually wrong with the bonded ICs (source drivers.)

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

r u talking about the buffers on the bottom of the set or the buffers on the top ?? If the one of the buffers were bad - wouldn't disconnecting 1 of the top ribbon cables display something on the screen ?? I've tried disconnecting them 1 at a time and no change.

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Hmm, that can mean that the problem could be away from the panel, so you've got that going for your at least. I'm not sure what the "buffers" you refer to are. This is an LCD TV, not a plasma TV.

Post a picture of the t-con, I can highlight some possible test locations.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

When I first turn the set on - white screen. push menu button - have some faint vertical lines on left side. doesn't display anything legible. looks like the tcon board isn't doing anything. black heatsink is cold. chip with rubber heatsink is warm (metal can container is heatsink - not shown on pic).

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

I need to be able to see the very fine print on that board, can you get a picture in focus? If not possible at a further distance, break it into quarters and take a photo of each, with a little overlap. Sunlight is a great diffuse light source, avoid flash if possible.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

When tv first turned on - (takes about 20 secs) totally white screen. press menu, screen has color vertical bars. phone pics of TCON board close up (4 quarters).
apologize for pics - camera battery is dead and can't find charger ! noticed that TCON board is not readily available

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Can you see any labels VONE, VOFFE, AVDD as I can't...

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

looking now - but something else I see - is power to tcon board going thru LVDS cable ??? no other cables attached to it ????

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

Yes, it comes through the LVDS cable.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

OK - signals are label on back of board - see pics (found camera charger - real camera pics !)

AVDD is pic 1 top left, voffe is middle left, Vone is very top left

[tom66]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

It's a bit awkward but can you solder wires to each of those points, label them or colour code them, and test with board in place? Note, be very careful not to short them you could damage the panel or t-con.

[ajshoe]

Re: 2008/9 Samsung LN55A950 Displaying Horizontal Lines

can do - VONE, VOFFE, and AVDD (there also a AVDDb). what am I looking for ?

turn power on - 30 seconds later - have totally white screen. see pic