On the first power up of my newly received 3018 CNC, one of the fuses was blown (exploded). After the very traumatic experience however, I figured the pcb had been touching the aluminum frame and after removing it from the frame, the board powered up and surprisingly, everything seemed functional. I was able to load grbl v 1.1 on the ATmega chip and using candle I was able to turn spindle on/off and have movement on all three axes.
Even though things seem to be working, I am still paranoid to do anything more serious due to the blown fuse. A simple continuity test suggests F3 is not having current through. Is there a way to figure out what this fuse is for? I am not able to find any schematics for this board.