Tab bond issue - Samsung LN46A550 LCD TV

On a modern LCD TV screen, white (or any color) vertical lines appear when the individual "tab bonded" wire connections of the ribbon cable servicing a column of pixels on the LCD display begin to fail.
From: https://www.nxp.com/wcm_document...
If the column wire is damaged and "stuck high," one of the 3 LCD display colors will show as a solid line.
From: http://www.avsforum.com/forum/16...
If the line is white, all three colors are "stuck on."
This could be a manufacturing defect of the panel, or a result of the TV operating in harsh temperature conditions.
Alternatively, the timing controller board (t-con) may be failing and not sending signal to the display in the first place. It could also be a loose connection of the ribbon cable between the t-con and display.
Test sequence:

• Reseat ribbon cables from display to t-con.
• Try replacing t-con. (Sometimes, solder re-folwing the t-con fixes the issue)
• Try replacing display. (Or, try applying pressure to the tab bonds)

Repairing the tab bond of an LCD display is a daunting, specialized task. Some folks have managed to fix them with heat guns or shims between the case and LCD (e.g., [Front Page] - Article: Howto: Repair LCD Tab Bond and TCON Issues), but those are hacks, at best.

Hi
Check its back-light CCFL lamps. Gopakumar Gopalan Google

Thats usually caused by bad flex tab bonds on the LCD panel itself. If you search for flex tab issues vidoes it will show how the pisture can get slow motion in areass as well as double images in that area.

flext tab bond is the most likliest cause. They tend to lose their bonds and then usually hitting the top edge of the screen will lock it in. Flex tab issues will make part of the screen take on distortions and slow response of the pictures movements in the screen

the samsung LNt 4661F has been known to develope flex tab bond issues which will cause line to run across the screen and you can also gt darker bands that run across the screen when the tab bonds fail. usually flexing the screen frame or a light tapping will allow the lines to disappear when its warm if its a tab bond issue

the tab bonds on the lcd panel where they attach to the Drive circuits above the TCON samsung is famous for bad flex tab bonds. Does the screen appear llike its in slow motion and double immages in that half of the screen as well as appear to have dark bands aross the screen? If so its probably the flex tab bonds.

Samsung and sony panels are mfctd. at the same plant in Korea. Tab Bonding Problem. I have same problem with my Samsung LN40A750. Read-on...I too have had this problem with the very same model, it is most often improperly diagnosed as a t-con board issue by most who just want to provide an answer for the sake of there own ego at various forums. This is a manufacturing defect. I have been dealing with Samsung for over a month now and have been offered a replacement model of lesser quality(LN40C650L1F) at a prorated cost of $300.00 to me which I have not accepted as of yet. My TV began having this issue almost exactly 1 year beyond warranty period. Typically it will only happen when TV is cold(if temp in room falls to approx. 68 deg or lower). When cold due to naturally occurring shrinkage as with anything, the tab bonding contacts to the screen are broken and therefore gives you 3 thin horizontal lines across separating the screen into four quadrants vertically and blurry details of everything including channel info, menu info, etc. It goes away after several minutes of warm up time, as the unit warms up expansion of the panel resumes and contact through the defective tab bond is made and picture is back to normal. A quick test to determine this is if you gently squeeze the bezel(frame) around the panel at the top left corner approx. 2 to 4 inches from the corner(this is where the defective tab is located for this particular problem) the problem will go away until the unit is turned off and has ample time to cool off again. When you squeeze you are effectively forcing the tab bonding back together and contact again is made. Another way to diagnose would be to turn your thermostat in house up above 72 degrees or so and wait a few hours for the TV to acclimate to the temp(expand) .This is why if left alone for a few minutes to warm up the problem disappears. Consequently people who keep there homes on the warm side, say above 70 deg. don't often see this problem, but the more heat-cool cycles the units go through the more likely this problem will rear up its ugly head.I believe this defect will pop up eventually on all samsungs produced with the same tab bonding method or materials that were used for however long they were manufactured that way. Naturally everything moves(expands and contracts) through heat-cool cycles but proper engineering methods or materials should prevent something like this from happening for at least, lets say 10 years, the average life expectancy one would expect to get out of a $1500.00 or more purchase depending on screen size. Common sense would dictate larger screens would be more prone to this problem due to more movement and smaller less prone. Unfortunately there are numerous tab bonds all across the top of the screen(panel) and different ones affect different functions of the operation of the set, therefore there may be many other various problems people may be experiencing with there samsungs due to a failure of one of these tab bonds. They are often erroneously diagnosed as circuit board failures due to laziness on the part of the tech. I would recommend to anyone experiencing intermittent or any problems to gently squeeze all along the top of the bezel to locate a defective tab bond. As for dealing with Samsung, all I can say is good luck, it is difficult to reach their corporate office and even more difficult to get a resolution. I would gladly join in any class action lawsuit if brought about as the one regarding their capacitor issue disappeared once they sought to start addressing the issue and this was only after an absurd amount of complaints to the NJ BBB and consumer affairs websites. I think they realize that they have a huge problem with most models manufactured in the last 3-4 years(primarily due to using cheaper components as a cost reduction/profit boosting solution) and as with any large corp., are not willing to issue any recall as it is cheaper to just deal with angry customers on a case by case basis, very unfortunate for them as their sales will suffer terribly because most people research on the web before making major purchases in today,s world and thank god for that.

Tab Bonding Issue. I too have had this problem with the very same model, it is most often improperly diagnosed as a t-con board issue by most who just want to provide an answer for the sake of there own ego at various forums. This is a manufacturing defect. I have been dealing with Samsung for over a month now and have been offered a replacement model of lesser quality(LN40C650L1F) at a prorated cost of $300.00 to me which I have not accepted as of yet. My TV began having this issue almost exactly 1 year beyond warranty period. Typically it will only happen when TV is cold(if temp in room falls to approx. 68 deg or lower). When cold due to naturally occurring shrinkage as with anything, the tab bonding contacts to the screen are broken and therefore gives you 3 thin horizontal lines across separating the screen into four quadrants vertically and blurry details of everything including channel info, menu info, etc. It goes away after several minutes of warm up time, as the unit warms up expansion of the panel resumes and contact through the defective tab bond is made and picture is back to normal. A quick test to determine this is if you gently squeeze the bezel(frame) around the panel at the top left corner approx. 2 to 4 inches from the corner(this is where the defective tab is located for this particular problem) the problem will go away until the unit is turned off and has ample time to cool off again. When you squeeze you are effectively forcing the tab bonding back together and contact again is made. Another way to diagnose would be to turn your thermostat in house up above 72 degrees or so and wait a few hours for the TV to acclimate to the temp(expand) .This is why if left alone for a few minutes to warm up the problem disappears. Consequently people who keep there homes on the warm side, say above 70 deg. don't often see this problem, but the more heat-cool cycles the units go through the more likely this problem will rear up its ugly head.I believe this defect will pop up eventually on all samsungs produced with the same tab bonding method or materials that were used for however long they were manufactured that way. Naturally everything moves(expands and contracts) through heat-cool cycles but proper engineering methods or materials should prevent something like this from happening for at least, lets say 10 years, the average life expectancy one would expect to get out of a $1500.00 or more purchase depending on screen size. Common sense would dictate larger screens would be more prone to this problem due to more movement and smaller less prone. Unfortunately there are numerous tab bonds all across the top of the screen(panel) and different ones affect different functions of the operation of the set, therefore there may be many other various problems people may be experiencing with there samsungs due to a failure of one of these tab bonds. They are often erroneously diagnosed as circuit board failures due to laziness on the part of the tech. I would recommend to anyone experiencing intermittent or any problems to gently squeeze all along the top of the bezel to locate a defective tab bond. As for dealing with Samsung, all I can say is good luck, it is difficult to reach their corporate office and even more difficult to get a resolution. I would gladly join in any class action lawsuit if brought about as the one regarding their capacitor issue disappeared once they sought to start addressing the issue and this was only after an absurd amount of complaints to the NJ BBB and consumer affairs websites. I think they realize that they have a huge problem with most models manufactured in the last 3-4 years(primarily due to using cheaper components as a cost reduction/profit boosting solution) and as with any large corp., are not willing to issue any recall as it is cheaper to just deal with angry customers on a case by case basis, very unfortunate for them as their sales will suffer terribly because most people research on the web before making major purchases in today,s world and thank god for that.

Its a TAB bond Problem with the LCD. You can take apart the TV and install a rubber Bumper to put pressure on the TAB. TAB bonds always get worse... I dont know how long it will solve the issue... but u can get a little more life out of it.
Rember when working with the TV the voltages can kill!!
Heres a link to see someone fixing.
I have the same TV...same problem...common problem...unless u ask Sony.