Engineering Manager | Trail Runner | Stockholm, Sweden

24" iMac screen freeze

As some of the readers probably know I am a proud owner of a 2008 aluminium iMac (model 8,1).

However, lately I am being plagued by a very annoying and – so far – unavoidable issue: during use at a random point the screen just freezes, something like a permanent screenshot. I can’t tell when it happens, can be weeks without it coming up at all or just after a few hours of being switched on. Sometimes the mouse still works but no input is registered. The machine usually keeps running and – for example if iTunes was on – music keeps playing in the background. I can use ssh to log in to the machine as well.

In order to put the machine out of its misery the only solution is a hard reset. (Or issuing a reboot/shutdown command from ssh.)

I can’t really tell when the phenomenon started, could be around the 10.6.3 update.

I have tried the following methods so far:

So far none of the above helped and I am getting increasingly frustrated.

Some users reported that their video card/logic board was replaced by Apple, only there is no store in Hungary and I’m out of warranty… Regardless, I can’t tell if it is a software issue or a hardware issue brought up by software updates.

Update: So far it seems that Time Machine and the Firewire drive has to do something with the freezes. Unplugged it and freezing ceased, replugged as USB and I got a lockup within the day. Doing a long-term test now with no TM/drive.

Update 2: I have installed 10.6.5 yesterday, replugged the TM drive and only this morning I got another freeze. Apparently the patch did nothing to fix the problem. Testing with unplugged external storage once again.

Update 3: OS X just got endless beachballed while no TM drive was present. Back to square one. Apparently I’m not alone either.