Why do the fuses (F1 & F3) on the Main Board keep blowing?
F1 is related to the 24VDC motor circuit. Check motor leads, wires and relevant connections. Replace motor and/or gun if necessary. The higher torque-lower voltage motors in the new Prince guns, use more amperage at start up. This increased amperage may or may not cause the fuse to blow. It is recommended to change the existing AGC 2A 250V fuse (P/N 151-0001) with fuse 3AG 4A 250V (P/N 151-0043). F3 is related to the 120VAC circuit. Isolate slave motor, brake solenoid, 120VAC contactor and relevant connections. Repair and/or replace faulty components as necessary.