I've wiped the machine and re-installed the OS about 3 times. I've run Memtest86, it passes all four passes. Is it possible there's no clues in the logs? I am looking for 'grave' sounding messages, but I honestly don't know what, exactly, to look for.

The problem is there's A LOT of messages. I've tried sifting through the logs looking near the time of the crash, and I don't notice anything obviously strange, basically just normal looking logs and then boot-up messages.

Is it correct to assume that this means it was not an application that crashed? Here's what I've done so far to troubleshoot:Īfter power-cycling, I go into Console.App, and select 'Crash Reports' on the sidebar, it is always empty. The system crashes this way usually at least once and often a few times per day if I use it a lot. What I normally do is just power cycle the iMac as soon as I hear the fans spin up and the applications become unresponsive. If I keep waiting, the screen goes black and if I wait a longer time the black screen gets a circle with a slash through it. Eventually, I get the 'rainbow circle' (beach ball?) mouse cursor and I can't do anything else other than move the mouse around. I am not even able to restart the iMac from the Apple menu (it just doesn't respond). When the fans spin up like this, the applications I am using (typically Chrome, but others too), will work for a little while, ~30 seconds, and then become unresponsive. I've been having an intermittent problem with my late 2013 27' iMac for more than a year now and it seems to be getting more frequent.īasically, I could be doing anything on my iMac (or nothing at all!) and I suddenly hear the fans spin up to what sounds like max speed.

Late 2013 imac hardware