BFT garage door opener starts to move then reverses and shows E04 on the display.

Safety: Work with the door in the open position when possible and ensure it is stable.

• Check for obstructions: Remove any objects, cobwebs, or debris between the BFT photocell transmitter and receiver.
• Clean lenses: Gently clean the photocell lenses with a soft cloth and mild cleaner to remove dust and moisture residue.
• Verify alignment: Ensure the photocell heads are directly facing each other at the same height. Many BFT photocells have an LED that indicates alignment; adjust until the LED shows a stable ON state.
• Inspect wiring: Trace the photocell cables back to the control board terminals (often labeled PHOTO, SAFE, or similar). Tighten loose screws and repair any damaged cable sections.
• Bypass test (for diagnosis only): Temporarily bridge the photocell input terminals at the control board as per BFT manual to simulate a closed contact. If E04 disappears and the door operates, the photocells or their wiring are faulty and should be replaced.

Never leave the system with safety devices bypassed; restore proper photocell operation before regular use.