Hi! I have the same issue. When I tried to upgrade the CPU from the same i3 8100 to the same i7 8700 the system won’t turn on. When I came back to the original i3 8100 everything was fine.
Is it possible to upgrade the base model’s CPU to anything?
I read something about micro-code in the iMac’s bios, but the same iMac has the configuration with the same i7 8700 cpu. It must be compatible!
Where’s the catch ?