Opener attempts to run but stops quickly; lights flash seven times; door may move only an inch or not at all.

Safety first: Disconnect power before opening the motor housing. Avoid rotating the motor shaft by hand with power connected.

• Locate RPM sensor: On many Craftsman models, the RPM sensor is a small circuit board or plastic module mounted near the motor shaft with a slotted wheel passing through it.
• Check mounting: Ensure the sensor is firmly attached and aligned with the interrupter wheel. If it has shifted, remount it in the correct position.
• Inspect wiring: Follow the small harness from the RPM sensor to the logic board. Look for pinched wires, broken insulation, or loose connectors. Reseat the connector on the board.
• Clean interrupter wheel: Dust or debris on the slotted wheel can interfere with sensing. Gently clean it with a soft brush or compressed air.
• Replace sensor if needed: If the 7-flash code persists after cleaning and reseating, replace the RPM sensor assembly with a Craftsman-compatible part.
• Test operation: Reassemble the opener, restore power, and run a full open/close cycle to confirm the door moves smoothly without error flashes.