Just thought I’d post this update. I did a dry run to confirm that the Mac Mini 2018 CAN be ‘simply’ modified to run on a straight DC supply. By following my pinout diagram posted earlier, I was able to temporarily affix some jumpers to the appropriate header pins and clip lead those to the terminals of a SLA battery and the computer started up fine. No weird, multiple voltages required. Incidentally… I also tried a power supply I have laying around which is 100W @ 12VDC. As anticipated, the machine would not start from this supply as it is only capable off supplying ~8.3A. I imagine the battery is capable of 20A or more so it was the obvious choice for testing. I will be carrying out the full mod in the coming days/weeks and will post again after completion.
Daniel, I just opened up my 2018 Mini and measured the voltage (not plural) coming from the power supply connector as well as a continuity measurement of the logic board connector.[document: MacMini2018_DC_Connector.pdf] As with the 2012 & 2014 models, the logic board needs ~12VDC. That’s it. The people claiming the 2018 power supply is outputting multiple voltages have clearly never opened one up and measured it. There is no basis to support this information as I have just confirmed for myself. As for the claims that these machines run on a “strict voltage tolerance”, I’m not buying that either. I ran my last Mini (i5 2014) on 13.6VDC because the point was to power it with a LiFEPO4 backup battery. However (as noted in the drawing) the logic board connector shorts the pin marked with an asterisk (*) to 0V or GND. This is a little suspicious considering this connection is not made on the 20pin cable that connects the PSU to it. All other connections are mirrored. This could be Apple’s way of trying to foul...