Anomaly on lcd panel


macrumors regular
Original poster
Jan 12, 2013
St. George Island
Maybe I have this in the right forum now. I have a mid 2010 iMac. I noticed this stain or whatever on the upper righthand corner. Can anyone tell me what it might be? I have taken the glass off and cleaned both sides and that didn't help.



macrumors regular
Sep 11, 2013
More than likely dust that has been sucked up inside the LCD itself. It's practically baked onto the glass part of the LCD. The LCD screen is layers (like a sandwich) of 3 plastic sheets and the actual LCD (glass bit). I had the same problem on a 2009 iMac. It first appeared on my iMac in 2010. It was way worse than yours though, and got really bad last year. I found a replacement on ebay (you have to get an LCD that is compatible) for around €200.

On a grey or white screen you can really see it. It was in the centre of my screen - so it interfered with colours when I was working on projects.

Yours is kinda out of the way though, so you might be able to live with it for another while.


macrumors 6502a
Aug 11, 2012
I've had this problem on a mid-2011 iMac, I believe it was.. I had to take it in to Apple to fix it a few times. They ended up giving me a new iMac after the first time, because whoever worked on my computer scratched it up.

The second time I took it in, the guy told me I should keep an air purifier near the iMac, which I did/do.

The third time I took it in, the guy tried to tell me it was my fault and that water must have been spilled on the iMac or it was in a very humid room. They ended up fixing it after I told him he was full of ****.

So, what I gathered from the folks at my local Apple store was that, as Mossy said, the dust gets inside the panel from that vent in the top/back of the iMac and it seeps through the panel since it's just magnetized.

SOoo.. I got a new iMac.. which doesn't have that vent at the top and is secured with an adhesive.. and now it's on all 4 corners, plus two more areas at the bottom, of the screen, about one inch to the left and one inch to the right of the Apple logo.

I will be taking it in, but I am going to wait until after the holidays.
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