Chosen Solution

Hi, my i Mac shuts down after 3, 4 hours of using (even when its just left on and runs screen saver). It just happened one day and since then its happening all the time after using it for always similar (but not same) amount of time. It seems like it is overheating(?), as it doesn’t start again straight away. It doesn’t react to anything - I have to wait for some hours and then it would start again (and work 3-4hours only). When it shuts down it does it with random click of mouse or remote control. Its not hot in the back of the computer, just as usual(i didn’t check the bottom though). Two things i want to mention

  1. i was not using it for last 2 months (as I have been away)
  2. the Hard Disk is nearly full (of course i know it should not, but i backed up some data on it prior my trip) Does someone knows what could i check/do please? Thank you heaps!

If I had to guess, I’d say your power supply is bad – if you can use iFixit’s instructions to figure out exactly which model you have, we can point you towards instructions/parts for replacing it.