Mac Crashing after OS Upgrade

I am running an iMac (2Ghz Intel Core Duo 1GB 667Mhz DDR2 SDRAM - if that matters) running OS 10.6.5.

Computer was running totally fine until I upgraded to this OS (From 10.4 maybe?) so I could use my new iPhone 4.

Ever since then the computer will randomly crash - either the screen goes completely black or completely white. I have to use the power button to restart. The only programs I'm using most of the time are Firefox 3.6.13 and the Mail 4.4.

I've installed all updates and it's still happening.


Has anyone else had any experience with this? it seems more like a hardware problem but I was having ZERO problems until the OS update.

Any ideas of where to start fixing things? Reinstall OS? Take it to Apple? Run anything else on it? Are there other threads dealing with this problem?

Thanks!

G'day and welcome to the forums.

Trust you did a clean install of Snow Leopard as upgrading can cause some problems? Also suggest you download and install the OS X.6.5 Combo Updater direct from the Apple web site and not Software Update in the Menu Bar.


http://support.apple.com/kb/DL1324