I got an iMac 21.5. 3.33GHz, 8GB RAM new back in Dec/09. So I was browsing the 'net today and out of the blue the screen went fuzzy/crazy. It was as if it switched from 65 million colors to like 256. There were some funny lines that didn't belong, things weren't crystal clear, etc. Odd thing is the second monitor was fine, just the built-in LCD was having issues. When I rebooted, the screen looked fine for a split second just before it went wacky again right when it was done booting. Long story short is I ran the hardware test and now it works, even though the hardware test didn't find any problems. So I'm left wondering things like this: - Is this a common problem? - Why did it happen? - Will it happen again? - What happens if running the hardware test doesn't fix it next time? - The iMac was pretty warm, might it have overheated? See attachment for a photo of my screen so you can see what I'm talking about. Look at the background pic, the hood on the car, you'll see it's lost color shading, etc.