Can you guys tell what is wrong with this LCD TV? - AVS Forum
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post #1 of 13 Old 05-24-2010, 06:21 PM - Thread Starter
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My tv screen has these rainbowed colored lines on the screen that keep changing colors and are blinking constantly. Also sometimes for a few seconds it returns to normal. Do you guys know what the problem could be? Is is worth fixing or is it better to get a new TV? The tv is a Samsung LN52A580.

Thanks in advanced



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post #2 of 13 Old 05-24-2010, 07:06 PM
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bad tab bonds or more likely the TCON board is failing

If you're a gamer or interested in using an LCD TV as a primary monitor take a look at my thread on
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post #3 of 13 Old 05-24-2010, 10:20 PM
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Too much area for a tab bond failure. The TCON is the problem. If the TCON is not available you are going to have to replace the panel anyway.

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post #4 of 13 Old 05-24-2010, 11:51 PM
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Quote:
Originally Posted by display veteran View Post

Too much area for a tab bond failure. The TCON is the problem. If the TCON is not available you are going to have to replace the panel anyway.

yep thats why i said its more likely the TCON is failing

you are correct in that if the TCON is not available then a full panel replacement is necessary because some makes do not sell the TCON board separately

If you're a gamer or interested in using an LCD TV as a primary monitor take a look at my thread on
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post #5 of 13 Old 05-24-2010, 11:55 PM
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this may or may not be the correct TCON board for you panel. you need to take it apart to compare by the photo to make sure

http://www.shopjimmy.com/samsung-bn8...-con-board.htm

it is for a A550 (very similar model that shares many parts)

here is the photo of the board



if it matches this photo its worth a shot and your best bet for a cheap fix good luck!

If you're a gamer or interested in using an LCD TV as a primary monitor take a look at my thread on
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post #6 of 13 Old 05-25-2010, 11:46 PM
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Quote:
Originally Posted by frito View Post

yep thats why i said its more likely the TCON is failing

you are correct in that if the TCON is not available then a full panel replacement is necessary because some makes do not sell the TCON board separately

And it was a good call Frito. Tab bond failures of the column drivers usually cause a single line of distortion (sometimes a couple of lines but usually a single line).

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post #7 of 13 Old 05-25-2010, 11:48 PM
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Quote:
Originally Posted by frito View Post

this may or may not be the correct TCON board for you panel. you need to take it apart to compare by the photo to make sure

http://www.shopjimmy.com/samsung-bn8...-con-board.htm

it is for a A550 (very similar model that shares many parts)

here is the photo of the board



if it matches this photo its worth a shot and your best bet for a cheap fix good luck!

See that white 5 amp fuse in the middle of the picture? That's the most common failure component on this TCON.

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post #8 of 13 Old 05-26-2010, 01:08 AM
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Quote:
Originally Posted by raptor3k View Post

My tv screen has these rainbowed colored lines on the screen that keep changing colors and are blinking constantly. Also sometimes for a few seconds it returns to normal. Do you guys know what the problem could be? Is is worth fixing or is it better to get a new TV? The tv is a Samsung LN52A580.

Thanks in advanced

The fact that picture intermittently returns to normal tells me that the problem is most likely related to TAB; not the T-CON board, but it is difficult to say. The TAB in the flat panel display industry is used to mount driver chips between the glass of the display and the input circuitry behind the display - the contact resistance can build-up with time and significantly effect conductivity, in particular with the change in TV, as well as ambient temperature.

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post #9 of 13 Old 05-27-2010, 12:21 AM
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Quote:
Originally Posted by Extreme_Boky View Post

The fact that picture intermittently returns to normal tells me that the problem is most likely related to TAB; not the T-CON board, but it is difficult to say. The TAB in the flat panel display industry is used to mount driver chips between the glass of the display and the input circuitry behind the display – the contact resistance can build-up with time and significantly effect conductivity, in particular with the change in TV, as well as ambient temperature.

Boky

Allow me to correctly explain what tab bonding is.

The gate and source drive components to control the liquid crystals are mounted on flexible circuit boards (known as flexible printed circuits, or FPC, for short). These components are “bonded” to the FPC. This is a solderless method.

The FPC is then “bonded’ to the LCD panel glass with a special glue that contains tiny metal balls. These metal balls provide the conduction from the pads on the FPC to the pads on the panel glass. The balls are small enough so that if any find their way between the pads they will not short circuit adjacent pads.

If one of the components on the FPC fails, or the bond of one or more of the FPC pads breaks from the LCD glass, the entire FPC must be replaced. This is known as “re-tabbing” the panel.

A very expensive machine is required to heat the area where the FPC bonds to the panel glass. This softens the glue so the FPC can be removed. The pads on the glass are cleaned, new glue is applied, a new FPC is positioned, and the area where the pads are located is re-heated to activate the new glue.

The FPC assembly looks like a tab you would find on a filing cabinet folder indexing tab and that is where the term came from. Any component failure on the FPC or loss of bonding between the FPC pads and the panel requires a tab replacement and re-bonding.

Newer panel designs have eliminated the tab bonding requirements on the gate driver side of the panel (that’s the left side) by incorporating the drive components into the LCD glass. The column drivers (source) are still bonded to a FPC coming from the TCON board.

If the problem you have shared with us was caused by a tab bonding issue it would require the failure of one-third of all the tab bonds along the top of your LCD panel. That does not happen unless the panel has suffered severe physical damage. You have a TCON problem.

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post #10 of 13 Old 09-04-2011, 11:40 AM
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I am having the same problems with my Samsung LN52a550PF3. Identical to the images already provided. Split right down the middle. I have replaced the T-Con board and still have the same problem. Could it be the TAB Bonds? Picture is intermittent? Any help would be appreciated!
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post #11 of 13 Old 09-05-2011, 02:48 AM
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bad TAB

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post #12 of 13 Old 09-20-2011, 01:02 PM
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I have almost the same problem. From center to 3 inches left of center of the screen, it flashes intermittently with vertical lines, single colors. Sometimes it works fine, other times it freaks out, other times the lines are solid colors for minutes at a time. The geek squad guy told me that it is a problem with the panel and I'll just have to replace the TV.

Any help? email to carlkep@hotmail.com if you want to offer a suggestion.

Thanks
LL
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post #13 of 13 Old 09-21-2011, 01:18 AM
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You’ve been told correctly
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