4-3
Chamberlain
Relay or Motor Drive Circuit Failure
Opener lights turn on but motor does not run; logic board LED flashes 4 times, pause, then 3 times (4-3).
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Failed motor relay on logic board, Burned PCB trace, Loose motor connector, Surge-damaged logic board
How to Fix / Troubleshooting
Safety first: Unplug the opener before opening the housing. Do not attempt board-level solder repairs unless you are qualified.
Steps to fix:
- Check motor connector: Ensure the multi-pin connector from the motor harness is fully seated on the logic board.
- Listen for relay click: With the cover off and power restored, press the wall button and listen for a relay click on the board. If lights come on but no click, the relay or control circuit is likely bad.
- Inspect board for damage: Look for burned spots, cracked solder joints, or swollen components. Replace the logic board if any damage is visible.
- Test with known-good board: If available, temporarily install a compatible Chamberlain logic board to confirm the diagnosis.
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Repair Difficulty
Hard
4/5
Required Part
Logic Board (Motor Relay Circuit)
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