MCU 'toolboard_t0' shutdown: ADC out of range

First-time build here, using the parts from the default kit. I've seen other posts about this, and generally it seems that this issue is as a result of thermistor wires being incorrectly wired, incorrectly crimped, loose, etc.

Since I did crimp the wires as per the guide, I figured maybe this was the issue, and swapped out my hotend for one from my IDEX upgrade kit with the wires in the box (super long) to make the connection just to see if that helps. It seems the issue still perists. Any other ideas? Does the fan have to be connected to the board in order for the toolhead to speak to the system? I unplugged it for the time being because it runs at 100% speed and sounds like a tornado. Attached are pictures of my toolhead.