Display problem

Hi,

Can anyone explain what's going on with my screen? This is a typical image of what the problem looks like.

Cheers for any help.

Can you hook it up to an external monitor?

Nope, don't have one. I've done some googling and think it may be heat related. It happens when I'm doing lots of things, does this bear true? My graphics is running at 56degC, but I'm not doing much.

56C is not hot.

Graphics cards artifact under intense heat (95C+) which would lead to that. Is it just that one little rectangle or is it the whole screen?

If that's a screen shot you posted, it indicates GPU problems. No need to hook up an external. Without posting any details about your Mac and which version of OS X you're running, it's difficult for anyone to assist other than what you may already know.

What information would be of help?

Any particular info from he system profiler?

No just if it does that to the whole screen it's probably a bad GPU.

It does it to the active window, never done it to the whole screen. It can do it to the icons in the dock, if one is clicked and it feels like it.

Anyway you can open up the Mac and make sure the heatsink is making full contact with the GPU?