iMac freezing/randomly restarting

[Sam*]

Hello,

Yesterday my late 2006 17" iMac started causing me some problems. I am running 10.4.11 if it's any help.

Basically, yesterday I got a message on the screen saying there had been an error and I must restart the computer. Then today any time the processor or maybe the video card is being used while watching videos the computer either completely freezes or it just restarts.

It happens both when watching videos on youtube etc and while watching videos in VLC so it is not a flash issue.

I have ran the Apple diagnostic and nothing came up. I also reset the PRAM etc but still, nothing helped. Even as I type this, the computer feels slightly laggy so it may not even be videos that are causing the problems.

I did find some topics about people using Lion and the computer freezing. However, they were all able to use the mouse where as my mouse freezes and I can not do anything except manually power off. Also, as I said, I am running Tiger.

Does anyone have any idea what could be causing this problem?

Thanks for any help.

Sam


** Update - it also happens when no videos are playing and I am just browsing the web so there is not a connection to videos and the error

 

[yusukeaoki]

Are you talking about the Kernel Panic?

 

[cocky jeremy]

Mine did that. I used smcFanControl to up my fan speeds and things are fine now. So it was a heat issue, for me, at least.

 

[Sam*]

Are you talking about the Kernel Panic?

The first time it was but all of the other times the computer just shut down automatically.

Mine did that. I used smcFanControl to up my fan speeds and things are fine now. So it was a heat issue, for me, at least.

Thanks for the advice, I will give this a go when I get home from work.

 

[cocky jeremy]

Also, not sure if you use it or not, but the application Boom was causing random restarts too. I think it was version 1.1 that caused it, and 1.2 fixed it. But the combination of a few things fixed it for me, and i'm not sure exactly which one did it but:

1) smcFanControl
2) 10.7.2 beta
3) A small fan to control heat on the back of my iMac.
4) Boom 1.2 (I know this helped for a fact, but i had two issues random freezes AND random restarts. Boom was the random restarts, one of the other three fixed the freezing)

 

[Sam*]

Okay, so I got home from work and now the iMac wont even turn on... I think it may be dying on me.

All I get is the hard drive starting up, and it appears the computer goes straight into sleep mode as the white light comes on. I do not get the chime and nothing comes up on the screen, it just stays off but the actually computer is on.

Could this be a logic board failure?