21.5" IMAC with weird video issue on startup

[Wallierock]

Hi guys,

I've recently noticed that when I start my imac it displays a weird pixelated white screen. It occurs right before the log in screen and it's intermittent(Sometimes the screen startup normally). My Imac has the radeon 4670 and I have already checked if there were any firmware/software updates I needed. I have also ran the apple hardware test as well, but it did not find any issues. I've took a screenshot of the problem(flickr link). Any suggestions?

Thanks
Simon

http://www.flickr.com/photos/24547902@N06/4681353688/

 

[ice40i]

Did you ever figure out anything im having this same issue with mine as well but i have a 27" I5

 

[bigmacman]

That looks weird. Should contact Apple Care to find out what's going on.

 

[ice40i]

The funny thing is that i Hvae the exact same pattern on mine pixel for pixel blue screen on the bottom and everything