Sony 46XBR4 Shadow Problem - AVS Forum
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post #1 of 7 Old 11-22-2008, 10:44 AM - Thread Starter
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Hello,

I am having a shadow problem on my 46XBR4 TV. I am attaching pictures of the problem and info on the problem.

Problem Details
- Shadow occurs when TV is switched on after atleast 1 or 2 hours of being switched off
- Shadow occurs for about 3 to 5 mins and corrects itself.
- Shadow is very prominent on the text.
- There are about three horizontal straight lines on the picture in the middle of the screen.
- Shadow occurs prominently on the left of the screen. The right side looks okay.
- I have removed all inputs to the TV and switched on and see the problem appearing as you can see in the first couple of pictures.

Any ideas on how to solve this problem? Any and all help is greatly appreciated.

Thanks and Regards.
LL
LL
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LL
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post #2 of 7 Old 11-06-2009, 09:50 AM
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I was having this exact same problem. I was hoping someone had a reply for you but it looks like they didn't. Did you ever figure out what was causing this problem? I had the problem, it went away, and then another problem started occurring. The right side of the screen now is dark upon turning the tv on, then gets better and ok after about 15-20 minutes.

Anybody know what causes the above poster's issue and the following issue I have had?
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post #3 of 7 Old 11-06-2009, 07:42 PM
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Yep. The tab bond for the gate drivers on the side of the panel has lost its connection. If you gently pull on the top corners of the panel you will see the problem go away. Sometimes a gentle pull will make the problem go away for several weeks. The only permanent solution is to replace the panel. Sorry.

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post #4 of 7 Old 11-09-2009, 01:34 PM
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So there is no way to meddle with the tab bond on the gate drivers? Can you explain what that is exactly so I understand? I really don't want to replace the panel as that is as much as the tv! By the way I replied to you on the other post as well, I will try and post pictures of what it currently looks like when I can.
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post #5 of 7 Old 11-09-2009, 01:41 PM
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Actually, it looks like maybe this post might help me if I have the time right?

http://www.avsforum.com/avs-vb/showt...php?p=17429753
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post #6 of 7 Old 11-09-2009, 07:20 PM
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I’ll try to explain this without getting too wordy and without using illustrations.

The gate drivers are multiple IC’s located on the left side of the panel (as viewed from the front) which are mounted on a flexible circuit board that runs from the top of the panel to the bottom. If you have a 1920 X 1080 panel there will be 1080 lines driven by this flexible circuit board. The flexible circuit boards are known as “tabs” and are bonded to the panel with special glue. The right side of the panel contains another flexible circuit board (with multiple IC’s) to provide a common ground return.

The LCD panel scans each line from top to bottom. As each line is scanned, the source drivers (column drivers) determine which pixels will light for each line. This is how the TCON circuit times the digital RGB data from the video processor to put the information to the proper pixel.

The gate buffer IC’s on the side of the panel are set up in a “bucket brigade” fashion. If any of the IC’s fail (or if a bonding of the flexible circuit board to the panel occurs) the subsequent IC’s after that point will fail to operate. This is the same as the scan buffers on a plasma display.

Your panel has experienced a loss of bonding from the flexible circuit board to the panel and it has occurred at the top corner of the “return” end on the right side. Bonding a new tab onto the panel will fix your problem. Unfortunately, there are very few places that do this other than the manufacturer who repairs their own panels. This is about to change as some independent service operations are looking into purchasing the machine that can do this.

Can you do anything to fix this yourself? Most likely not.

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post #7 of 7 Old 11-10-2009, 12:49 PM
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Bummer there isn't much I can do, but I do really appreciate the explanation. I can still try calling Sony I assume however I know how calls like that end up...frustrating the end user. Might be my only option at this point.

Thanks again for your advice and replies!
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