Faulty screen or GFX?

[Cattywampus_]

Hi guys,

Switched my iMac white 20" at work on this morning and the screen was all messed up.

Had vertical bands of different brightnesses and horizontal lines going across the screen - very faint but are noticeable.

The computer has been on for about 2hrs now and the vertical banding seems to have faded for the most part but the horizontal lines are still present.

Have called Apple and they have told me to take it to a repair centre, but its out of warranty and am clutching at every straw to hope its something I can fix myself.

Anyone have any experience of this problem?

 

[AlexisV]

Can you post a screenshot?

 

[Cattywampus_]

Wish I had thought of that when the obvious vertical lines were there. I don't think you'd see the horizontal ones.

They are weird. Its like they appear and fade in and out. Reminds me of an old CRT when the refresh rate wasn't set properly.

 

[Cattywampus_]

How bizarre.

As the day has gone on the problem has cleared. The vertical stripes cleared first, then the horizontal lines cleared.

The only t hing I did differently last night before leaving work was leaving the computer switched on doing some automator scripts in the background. I set the screen to turn off after an hour, with the screen saver kicking in after 5 minutes.

People have suggested the cold through the night might have affected it?