iMac 27" 2017 random freezes

[Sdahe]

Hello,

I have a 27" 2017 iMac 5K for a year and now it's getting random freezes. The computer seems to keep working but I get no response from the keyboard or mouse. A few months back I installed Majove and everything was running smooth with no problems... how can I know whats happening?

 

[Lethcoeb]

If you search you’ll find more of these on the forum. I had a similar problem with the same model which I had to return. I had to unplug and replug before it would reboot, and eventually it would reboot at all. Contact Apple!

 

[Sdahe]

One interesting thing... I unplugged the external HD that I use for Time Machine and I haven't seen another freeze.. hummmmm

 

[CoastalOR]

One interesting thing... I unplugged the external HD that I use for Time Machine and I haven't seen another freeze.. hummmmm

Good catch.
Use Disk Utility to check the external HDD you use for Time Machine. If it has a problem then Finder can get bogged down trying to communicate with it.

 

[UbuntuFu]

I had random OS freezes where I had to turn it off by holding the power button.
Ran the Apple Diagnostic tests and it turns out I had a bad memory module.