opener light comes on but the motor doesn't run at all when i press the button. no sound, nothing.

Diagnosis

The Overhead Door Legacy 920 is experiencing a failure in the signal chain between the input trigger and the motor relay. Because the light illuminates, we know the 120V AC power supply is reaching the logic board and the transformer is functioning. However, the "silent" failure—where there is no humming, clicking, or movement—indicates that the logic board is not triggering the motor start capacitor or the motor windings. This is typically caused by one of three things: a broken wire in the wall station loop, a failed wall console button, or a blown capacitor on the logic board. If the "lock" feature on your wall console was accidentally toggled, the motor will be disabled even if the logic board is healthy. To confirm the root cause, you must determine if the logic board is receiving the "close/open" signal from the wall station or if the board itself has suffered a component failure (such as a burnt-out relay).

How to Fix It

Follow these steps to isolate the failure point and restore operation:

1. Check the Lock Feature: Look at your wall-mounted control panel. If the "Lock" button is engaged, the remote and wall buttons will not trigger the motor. Press the Lock button once to disable it and attempt to operate the door.
2. Bypass the Wall Station: Locate the "Learn" or "Program" button on the motor head unit. Press and release this button quickly. If the motor engages and the door moves, the logic board is functional, and the problem lies in the wall console or the 22AWG bell wire connecting the console to the motor.
3. Test the Wall Console Wiring: If the motor didn't run from the Learn button, disconnect the two wall station wires from the terminals on the back of the motor head. Use a small jumper wire or a paperclip to momentarily bridge the two terminals. If the motor starts, your wall console is dead and needs replacement.
4. Inspect the Logic Board: If bridging the terminals does nothing, power down the unit. Open the motor housing and inspect the logic board for "burnt" spots, bulging capacitors, or a smell of ozone. If you see a charred component near the relay, the logic board must be replaced.
5. Verify Sensor Alignment: While the light is on, check the safety sensors at the bottom of the tracks. If the LED on the receiving sensor is flickering or off, the motor will not move. Clean the lenses with a microfiber cloth and ensure they are pointing directly at each other.

If That Didn't Work

• Replace the Start Capacitor: The Legacy 920 relies on a start capacitor to give the motor the initial torque to move. If the capacitor has leaked or failed, the motor may stay silent. Look for a cylindrical component on the board; if the top is bulging or leaking fluid, replace the capacitor (matching the uF rating exactly).
• Check the Limit Switches: If the internal limit switches are jammed or have shifted, the board may "think" the door is already fully closed or open, preventing the motor from engaging. Manually move the door a few inches and try the button again.
• Test for Low Voltage: Using a multimeter set to DC voltage, probe the output pins of the logic board leading to the motor. If the board shows 24V output when the button is pressed but the motor doesn't turn, the motor windings themselves have likely failed.
• Inspect the Belt Tension: While unlikely to cause a "silent" motor, a severely snapped belt or a jammed drive sprocket can occasionally trigger a thermal overload protector. Unplug the unit for 30 minutes to let the thermal fuse reset, then try again.

Heads Up

• Wire Gauges: When replacing wall station wiring, only use 22AWG stranded bell wire. Using thicker household Romex can cause connection failures at the terminal blocks.
• Power Safety: Always disconnect the 120V power plug before touching the logic board or bridging terminals to avoid shorting the microprocessor.
• Sprocket Maintenance: Every six months, check the belt tension on the Legacy 920. A belt that is too tight puts undue stress on the motor relay and can lead to the exact board failure described above.
• Sensor Alignment: Even a 1/4 inch misalignment of the safety eyes can prevent the motor from starting, though usually, this is accompanied by a flashing light.