samsung 42" LCD lines after bad caps replaced LE40A456C2D

[karlpowell]

Hi folks, I picked up a samsung LE40A456C2D stuck in standby , I replaced the 4 bulging caps on the board marked in the picture , the set now boots up but i have lines on the screen (see video) , Ive been told this maybe just ribbon cable that has burned since over voltage with the bad caps but i cant see any problems with the cables.

If i move the set or apply a little pressure around the top of the inverter board the screen changes but the lines never go fully away.

http://www.youtube.com/watch?v=Tdihh...ature=youtu.be

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D



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[notallbad]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

Might be better to have a source input connected to show the full extent of the image defect.

Most likely bad tab bond, buffer or t-con.

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

OK ill get some more pics now ...1 min

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

these pic are all of the top right hand side of the screen

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

The owner assures me the screen did not have this fault untill the caps failed .

[johnboy1313]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

The last set I bought, the owner assured me that it worked intemittently and that he never opened it up. It's missing the LVDS cable. People lie. That doesn't mean your guy lied to you, but it does happen.

[notallbad]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

Very true!

It can lead you on a wild goose chase believing what the seller/original owner tells you, either because they want to get more for it or don't want to own up to doing something that they shouldn't have!

A picture of the whole view of the tv screen please, its to see the overall picture distortion not just a specific area. If its a good quality picture we can zoom and pan without loosing too much picture quality.

[Clydeuk]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

Afraid your panel is defective, these are single pixel lines which narrows it down directly to the drive ic or tab bond connection (panel side). Most likely the IC associated with that area (there appear to be 2 areas as well)

I doubt a bad power supply could cause this damage, I would suspect the person who sold this to you either:

Put up with this until the power supply failed. or

Bought this like this as a donor set, power supply pulled to fix another, old PSU fitted and sold as non working.

Sorry I know that's really negative but I've encountered this a few times.

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

I have another Samsung and the picture is a lot better on that than this , it can look a little washed out sometimes

[tom66]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

Panel's definitely bad.
Very common on these models.

If it was simply a loose tab bond you would have only dark or only lit up lines, but you have both. So the driver is defective.

It looks like cheap CHIMEI or CHUNGWHA panel, not very nice to watch. Proper Samsung use a SAMSUNG panel like LE40A656 which looks quite nice, though still doesn't quite look as nice as a good plasma...

[karlpowell]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

thanks Tom and everyone else who has replied.

[Clydeuk]

Re: samsung 42" LCD lines after bad caps replaced LE40A456C2D

I had a BEKO set with similar issues, when I dismantled the panel assembly to look at the tabs (out of curiosity) I discovered a couple were kinked (like a crinkle on the flexible print). Sure enough applying gentle pressure at the right place could cause some of these lines to disappear, or sometimes confuse the T-CON enough to crash the whole display. I believe that was a CMO panel as well. Think it's bad assembly at the factory that causes this to occur, and I don't believe it's particular to any manufacturer as Samsung panels themselves can suffer this problem. The fact is there are an awful lot of very miniscule traces on each tab to drive each column of each subpixel across the width of the display, doesn't take much to cause a problem here.