IMAC freeze

[Grnacres]

My IMAC keeps freezing up. Only remedy is hold down power button to reboot. I am running OSX 10.5.8. I have tried disk utility, repair permissions and it still keeps hanging up. Any ideas?

[Lifeisabeach]

It could be any number of things. Something running in the background locking up the computer. Faulty hardware. I would first run the Apple Hardware Test to see if perhaps you have bad RAM.
The Apple Hardware Test

Follow the instructions for Loop Mode in particular to test out the RAM more thoroughly.

If the hardware checks out, then try creating a new user on the computer and use that account for a bit to see if the problem replicates there. This will help narrow down where the problem lays.

[Grnacres]

Thanks. I will try the hardware test.