iMac has black "wavy" sections on the top of monitor

Hi all

I was wondering if you could help me understand if there is something wrong with my Mac.

I have noticed since Sunday at the top of my Aluminum 20" 2.4Ghz Imac little black marks in the shape of little waves. This is only noticable when the Mac is showing a black screen or is in sleep mode. So far it hasn't mucked the image up e.g. the menu bar looks normal.

I have been given 2 different opinions on what to do. One is that if it isn't mucking the picture up (which it isn't) then it should be ok, the other being to take it back. Just wondering if anyone could give me a clear opinion to it.

Attached is some pictures of the problem.

Advanced thanks for help.

Johnny

I can't quite tell from your included pictures, but it looks like some sort of interference. Do you have external speakers attached to the iMac which might be close to the LCD?

Try moving your iMac to another location and see if you get the same thing on the screen. If you do and it's not from interference, I would take it on in to your local Apple store and have them look at it.

Regards.

Hi chscag

I did have some speakers which were plugged in to my TV but not the iMac. These have been unplugged for a few days however the wave things are still there.

Have noticed however that when on a black screen on the screensaver for example, the waves now cannot be seen. It's only noticable when the display is off or in sleep mode.

Johnny