iMac 5k (Late 2014, 4GHz i7, AMD R9 M295X, Mojave) shutdown/crash.
My iMac 5k (Late 2014, 4GHz i7, AMD R9 M295X, Mojave) starts to shutdown/crash casually without no visible trace why.
It comes suddenly without any repeatable pre-action, which could show why. It shuts down completely, like an electricity cut.
To start it over, it requires to remove-wait-plug power cable. And then only it starts.
First, it starts, while running a game, so I was thinking it's overheating or corrupted game file.
But now it could happen on a 'cold' mac (GPU 60C, CPU 50C).
Sometimes it's even during the MacOS loading.
After it happens once, it becomes more and more frequent over time. Until it shutdown on load...
The only thing which helps - when it stays shut down for a while. Then you have some time to work...
Here the list what had been already done:
Apple Hardware test (Option+D on boot) - No issues found
RAM test (ramber) - No issues found
GPU Extreme-load ~10min (Unigine Heaven) - No issues (temp 105C)
CPU+GPU Benchmark test (Geekbench 5) - No issues
Re-install of MacOS Mojave from Recovery (CMD+R) - Did not help
Reset of NVRAM (CMD+Option+P+R) - Did not help
I don't know what I can do more - what to test, how to find the issue.
Or, at least, to understand is it software or hardware...
Thanks.
System details:
OS: macOS Mojave 10.14.6 (Build 18G2022)
Model: iMac15,1 (27-inch Retina, Late 2014)
CPU: Intel Core i7-4790K @ 4.00 GHz
RAM: 32GB 1066 MHz DDR3
GPU: AMD Radeon R9 M295X 4GB
iMac with Retina 5K display, macOS 10.14