Disconnect the magnetic switch and directly connect the 2 yellow wires together to test the air curtain. If the air curtain can turn on and off by toggling the 2 yellow wires, the air curtain is functioning. Just need to replace the magnetic switch. Please review the magnetic switch video
to make sure the effective surface is mounted correctly. If the air curtain is still off after connected the 2 yellow wires together, the circuit board might be defective.