Chosen Solution
I tried to upgrade one of the 2 HDDs to an SSD, and when I reassembled the Mini, it started overheating because the fan didn’t come on. Opened it up again, checked all connectors, same issue. Put in a new fan, same issue.Put in a new HDD sensor, same issueDisconnected HDD sensors, same issueRe-installed original HDD, same issue. I’ve also zapped the NVRAM, and of course SMC resets after you’ve had it unplugged anyway. Any ideas?
I would do a detailed visual inspection to see if one or more components got damaged around the plug areas. Here’s two useful images to reference against:
