Chosen Solution

Hello! I wanted to update my old Mini A1283 with a working SSD from a dead laptop. I also cleaned it and completely tore it down, including removing the heatsinks for changing the thermal paste. If I start it up the light turns on, there’s no chime and the fan slowly spins up to about half speed and then slows down. It doesn’t respond to anything except from the power button. I tried everything (rebuilding it entirely, changing the RAMs, trying a single slot, resetting the SMC, changing the internal battery, even trying if it does the beep without the RAM). Nothing. I read on internet that, if I press for 5 seconds the power button while I insert the power cable, release the button and press it again to turning it on, it resets the PMU or another thing inside the Mini. If I do that, my Mini starts with the fan at top speed. In MacOS SMCFanControl or Macs Fan Control shows neither fans nor temp sensors, but the Mac works fine and shut downs and restart as when it was new (except from the fan) until I remove the PSU. Then I have to reset the PMU again. Is the logic board fried, or there’s something else I can try? Thanks in advance for the help. Federico P.S. I found some working logic boards like mine on Ebay for around 60 Euros including shipping…. Update (11/27/2017) Sorry for the late answer, but I was on holiday… Here’s a photo of TG Pro:

https://drive.google.com/open?id=1KrzkVy

First did you follow this IFIXIT guide: Mac mini Model A1283 Hard Drive Replacement? If you jump down to Step15 &16 it describes the process of disconnecting the thermal sensor which you need to transfer to the new drive. If you did you don’t need any software to control the fan. Who’s drive did you put in (make & model)? And what was the OS-X version your system is running now? Update (11/28/2017) Wow! Haven’t seen a blown SMC in quite awhile. Your SMC services are no longer working at all! This is a logic board repair or replacement. Sorry ;-{