The power supply is the box to the lower right. Any of the yellow wires coming from it are 12VDC and the black ones are ground of course. In this machine all the 12 volt lines are on when the PSU is on and off when it is off. If you want to control it you will need to install your own switch near the fan. I would suggest just to let it run all the time as it will keep the board running cooler in general.
The large white connector middle left also is 12 volts and ground supply for the board. A fan could be tapped in there as well.
Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.