my iMac (late 2015 27inch 5k) keeps shutting down. I have to unplug it then plug back in and press the power button to restart it. Its been happening for the past 6 months but getting worse. Sometimes i have to unplug from the computer vs the wall outlet. I reinstalled the OS and still having these shutdowns. Any suggestions?
iMac 27", macOS 10.14
If it still will not stay on, then you need to make a service appointment at your local Apple Store or AASP.
If it still will not stay on, then you need to make a service appointment at your local Apple Store or AASP.
I had the same issue and it took a few months for us to solve it. I explained the details here. https://discussions.apple.com/thread/250053947
I took the machine to Apple's genius bar several times and we tried different solutions from reinstalling clean Mojave OS from server to changing SSD (Which I am not sure if your model has it or not) and finally they changed the power unit and Hard Disk at the same time and it's been fixed since then. I had apple care and they did it for free but if you don't have that I suggest start with changing the Power Unit as it makes the more sense.
Random shutdowns
