after a power outage my craftsman opener just blinks its light once and won't run

Diagnosis

The Craftsman 57915 utilizes a logic board that is highly sensitive to voltage spikes and sudden drops, which commonly occur during power outages or when power is restored. When the unit blinks its light once and refuses to trigger the motor, it indicates that the control board has entered a "fault state." This is essentially a software lock where the system believes the door is in an unsafe position or that a safety sensor is obstructed, even if the sensors are clear. This specific behavior often stems from the capacitor failing to discharge fully during the outage, leaving residual current in the logic board that prevents a clean reboot. Because the 57915 is a belt-drive system, the motor requires a specific burst of torque to overcome the initial inertia of the belt; if the logic board is stuck in a fault loop, it will cut power to the motor immediately after the initial relay click (the single blink) to prevent motor burnout or gear stripping.

How to Fix It

To clear the logic board and reset the motor's starting position, follow this precise sequence to perform a hard hardware reset:

1. Disconnect the power cord from the 120V ceiling outlet. Do not simply flip a breaker; physically unplug the unit to ensure the circuit is broken.
2. Locate the red emergency release handle on the trolley. Pull the cord straight down to disconnect the carriage from the belt. This removes all mechanical tension from the motor, allowing the logic board to calibrate without resistance.
3. Wait exactly 60 seconds. This allows the capacitors on the 57915 logic board to fully drain, clearing the temporary memory of the fault state.
4. Plug the unit back into the ceiling outlet. You will likely see the light flash once or twice; this is normal initialization.
5. Press and hold the "Learn" button (usually a square purple or yellow button on the side of the motor housing) for 5 seconds, then release. This refreshes the board's internal state.
6. Manually slide the garage door to the fully closed position.
7. Pull the red emergency release cord back up and slide the carriage back into the trolley until it clicks firmly into place.
8. Press the wall button. The unit should now engage the belt and move the door.

If That Didn't Work

• Check the Safety Sensor Alignment: Power surges can occasionally "blind" the infrared sensors. Look at the LEDs on the sensors at the bottom of the door tracks. If the green light is flickering or the amber light is off, the board will refuse to run the motor. Wipe the lenses with a microfiber cloth and ensure they are pointing exactly at each other within a 1/4 inch margin of error.
• Test the Wall Console: The wiring in the 57915 wall button can become brittle. If the motor isn't responding, bypass the wall console by pressing the large button on the motor head itself. If the motor runs from the head but not the wall, you have a short in the low-voltage wiring caused by the power spike.
• Inspect the Start Capacitor: If you hear a humming sound for two seconds followed by a single blink, the start capacitor (the cylindrical component on the board) has likely blown due to the power surge. This requires replacing the capacitor with a matching microfarad (µF) rated part specifically for the 57915 model.
• Reset the Travel Limits: The power outage may have wiped the "limit" settings. Use a screwdriver to turn the "Up" and "Down" limit screws on the side of the motor housing by 1/4 turn each, then attempt to run the door again to force the board to re-recognize the door's position.

Heads Up

• Surge Protection: The 57915 logic board is notorious for frying during lightning storms. Install a dedicated garage door opener surge protector at the outlet to prevent future board failures.
• Belt Tension: After a hard reset and manual release, check that the belt hasn't slipped. There should be about 1/2 inch of play; if it's sagging, tighten the tension nut at the end of the rail.
• Lubrication: While the system is disconnected, apply a silicone-based lubricant to the rail. Never use WD-40, as it attracts dust which can cause the motor to strain and trigger another fault state.
• Battery Backup: If your model has a battery backup, check the date on the battery. An aging battery can cause erratic behavior and "ghost" blinks during power fluctuations.