Chosen Solution
Mac Pro mid-2012 This machine has been cutting out periodically for about a year. There are two problem areas. Firstly it cuts out when put to sleep. Secondly it cuts out randomly, perhaps after several weeks untroubled usage. It’s very unpredictable in this respect. To get round the first problem I changed the energy save settings to let the screen sleep but not the computer [moving the pointer to ’never’]. Obviously this doesn’t solve the random cut-outs. Apple had it for two weeks. They found nothing and suggested a software problem. I think that’s wrong. It’s baffling and resetting the PRAM/SMC hasn’t worked [I did this myself and am certain Apple techs did the same as the first order of business] but since reading the advice dispensed to iMac owners with similar problems I now suspect something more serious. Apple STUMPED - iMac shuts off randomly, daily to multiple times/hour iMacs are not Mac Pros but is the weakness likely to be the same [logic board/power supply]? I’m guessing things will get worse over time so naturally I’m quite anxious to solve the problem. It’s unfortunate I’m very much a non ’techie’ type, and that these things are often too complicated to simplify for people like me, but with things as they are I’d just be terribly grateful for some advice. Thank you. Jack
My experience with the 2009-2012 Mac Pros has show a problem with the power supply. I’ve had several that will restart on their own. As time goes by the frequency of these restarts accelerates. On every one of them, replacing the power supply solved the problem. The other main issue with these has been failing video cards, (my 2009 is on it’s third). There also appears to be a sleep issue with Sierra. I have noticed that in the last couple of months I now have to press the power button to wake up after my machine has slept. I believe this to be an issue with a Sierra update. It is not happening with El Capitan.
