There are 3 fans inside the fridge. 1 in the upper, two in the middle - one of them moves air between the lower to upper, the other directs air between the rear to the lower.
The fan in the upper area wasn't spinning at any time, the other two were. I switched the connections around and found that whatever fan is plugged into the connection for the upper compartment will not spin.
I also found that there is a second humidty/temparature sensor sitting next to the fan that directs air from the rear to the lower compartment. I then re-connected the original sensor that I replaced earlier (it's in upper compartment) and swapped this new one for the othe sensor i found.
The fridge is running right now, and I'll see what happens in another day or so. I'm pretty sure the issue with the fans means there is a problem with the control board, and this could also be causing the temps to read wrong (or not at all).
Should I be looking to replace the controller or scrap the fridge?