I have been the owner of an iMac 27' for the past 3 years. I have had the problem of the machine automatically powering off (for no reason at all) since almost day 1. After trying everything, including having the local iCentre change almost every part, I am still struggling with this problem.
On the UPS display which I have attached to the same mains the iMac is attached to I have started noticing that the voltage input fluctuates between 230v and 237v (I believe that in our country the voltage should be 240v). Does anybody know if the iMac has an inbuilt mechanism to shut off automatically as a protection mechanism when voltage fluctuates?
Did anyone encounter the same problem? Do you recommend any particular UPS / stabilizer?
Update: My error message is
'Previous shutdown cause: 0'