My screen goes black and imac is unresponsive

[shujin]

Hello

I have been experiencing some unusual problems with my imac. While on the internet today my computer crashed on me twice, the first time the screen just showed a bunch of vertical lines, the second it flashed some random colors then went black. After the screen change the computer was unresponsive. I have a bad feeling, is it due to overheating, a bad logic board or something else. This is the first time I have ever experienced this on a mac. Has anyone had any simiar issues? Or am I up **** creek? I can't really afford a new computer seeing that I just bought an iPad (it comes Saturday). I am not sure if my computer is still under apple care and even if it was I won't get it back by the time I have to go back to college. I attached a screen shot of my computer temps.

 

[shujin]

It happened to me again. This time I snagged a picture of it. Hopefully some one has an answer.

 

[wetrix]

Have you had any luck finding out what was wrong or how to replicate this problem? I've been having the same thing happen lately on my 24" 2008 iMac.

 

[Dwhite78]

It happened to me again. This time I snagged a picture of it. Hopefully some one has an answer.

Bad video card and or logic board. Happened to my wifes 2008 imac 3 times. Had to replace hardware all three times.