Chosen Solution
Whenever I plug in the Mac Mini the Fan continues spinning but no signs of life in any sort of way. No LED indication or display on screen. I did a CPU/RAM Upgrade about a year ago and it worked for a month but after I did a disassembly I resembled the computer and it stopped working. It could be a power supply issue but I still have no idea , wasn’t gonna take it to get repaired because this is my personal project computer. Any help or tips would be greatly appreciated …… Thanks IFIXIT :}}}}
The fact the fan is running is telling us your system is getting power! I would put back the original RAM to see if you put in the correct units as well as see if they are good. You talked about upgrading the CPU, a common issue I see is people over doing the thermal paste. after first checking the RAM I would go back and pop off the hat sink and inspect thiegs. Before you alter things take a picture so we can see things and post it here so we can as well Adding images to an existing question.
