crwdns2933897:0crwdne2933897:0

2017 27" iMac intermittent shutdown

How do I confirm that the problem is the power supply in my 2017 27" iMac?

It shuts OFF completely after it has been ON for a while. Seems to be more often since the weather is warming up.

But one of the key items is that I must 'unplug' the AC power cord for several minutes before it will power back ON.

There also seems to be concerns with the CPU and GPU thermal paste drying out. I will try that fix, but I’m still thinking the power supply needs replacing as well.

I have done older iMac repairs and upgrades, so I am OK inside the system.

crwdns2934089:0crwdne2934089:0 crwdns2934093:0crwdne2934093:0

crwdns2934109:0crwdne2934109:0

crwdns2853045:0crwdne2853045:0 crwdns2853046:0crwdne2853046:0
crwdns2889612:0crwdne2889612:0 0

crwdns2947414:01crwdne2947414:0:

I would start off by running the onboard diagnostics, restart your system and press the D key to enter.

Reference: Mac startup key combinations Did you get any errors?

crwdns2934271:0crwdnd2934271:0crwdne2934271:0

crwdns2934285:0crwdne2934285:0