IMac freezing during video games

[danielpuente]

I recently (3 days of writing this) was playing World of Warcraft and my Mac completely froze. The only way to escape this is by turning the computer on and off. Ever since, any time I open a video game application, within a few seconds my Mac will completely freeze. On occasion my screen will freeze but my mouse will work, albeit in reverse (left is right, up is down, etc.) and will move incredibly fast. No other applications are affected in such a manner and since this is only occuring during graphics intense video games, I suspect my graphics card is causing this. If there's anyway to check this before bringing it in to the shop, I would love to know.

[JeffCGD]

If your Mac came with a hardware test CD, you can boot from that and run tests on your graphics card, among many other things.

It could be hardware, or it could be corrupted graphics system drivers (from that original crash). Try downloading and installing the 10.5.7 Combo Update over your current install (Backup first, of course), which should replace any damaged System files. If it's still doing the same, I'd look to hardware.

If you take your iMac in, be sure you back your machine up first, as if your graphics card is damaged they may well replace your entire machine instead of tearing it apart to get to the graphics card, which tend to not be too serviceable. Even if they do just replace the part, they may do a fresh install on the HD to rule out any software issues.