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You are here: MacNN Forums > Hardware - Troubleshooting and Discussion > Consumer Hardware & Components > LCD blotching/clouding/mura

LCD blotching/clouding/mura
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Ted L. Nancy
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Aug 19, 2011, 12:15 PM
 
I really hope to get some good advice with this one...

I have a large Westinghouse LCD that I use in a home theater setup. The pictures more or less illustrate the problem:





(The white streak in the top picture is camera glare. The dark blotches are the problem.)

This began to develop about a year after I bought it. It hasn't gotten any worse than this for some time now. It is most noticeable with solid blue or gray colors.

At first, I thought I made a big mistake mounting the TV above my fireplace. Heat damage, perhaps? I'm inclined to say "no" for 3 reasons: 1) I've held my hand near the LCD when my fireplace is on "full blast," and the amount of heat up there is nothing to get excited about. 2) Why me? Plenty of American's mount TV's over their fireplaces, yet this doesn't seem to be a widespread problem. 3) This same problem happened to a 20" Dell LCD that I had used with my laptop for a few years. That screen was never near any heat source. I can't imagine what these two screens have in common, as they were used in totally different environments/applications.

Could it be that I have it mounted at an angle (using a tilting wall mount)?

Could it be that this was a refurbished model?

If this is just a defect that I have to live with, then fine, but I would still like an explanation as to why it happened with my Dell.

Google and forum searches have yielded all sorts of crazy ideas, including not using your LCD screen in a "dark room," which is just impractical for me. Some people have said turning down the screen brightness, holding a magnet behind the screen near the problem areas, and removing the screws from the back panel to relieve "pressure."

I'm looking to upgrade to a larger/nicer screen in the next several months, but before I do, I want to get to the bottom of this so that it doesn't happen again. Also, if there is a way to repair my Westinghouse, I'm all ears, as I would like to use this TV in another room.

Thanks,

Ted
( Last edited by Ted L. Nancy; Aug 20, 2011 at 05:16 PM. Reason: fix picture links)
10.7.1 on Mac Pro 8x2.8
     
P
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Aug 20, 2011, 06:26 AM
 
Can't see the picture, but...Heat is the most likely answer. I know that Samsung has a problem with their ultrathin models, where the backlight diffuser gets overheated and produces a clouding effect.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
revv9k
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Dec 21, 2011, 02:34 AM
 
Did you ever get this figured out? I have the Same TV and I am having the SAME EXACT issue. Its so hard to google becuase it LOOKS like water damage but it is not.
     
Ted L. Nancy  (op)
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Dec 21, 2011, 08:47 PM
 
I was never able to resolve this.
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P
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Dec 22, 2011, 05:39 AM
 
Now that I can see the pic, I think it's a case of overheating in the diffuser layer.
The new Mac Pro has up to 30 MB of cache inside the processor itself. That's more than the HD in my first Mac. Somehow I'm still running out of space.
     
   
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