DIAGNOSIS The wall control panel has no power. This is almost always a wiring issue between the motor unit and the wall mount.
FIX Check the connections at the motor unit. The wall panel wires connect to terminals marked '1' and '2' on the opener's back panel. Ensure the wires are securely under the screw terminals and not touching each other. Next, inspect the wire run for damage, especially where it enters the wall or near the door track.
IF THAT DIDN'T WORK The wall control unit itself may have failed. To test, temporarily disconnect the existing wires from terminals 1 and 2. Touch the bare ends of those two wires together briefly. The door light should turn on. If it does, the wiring is good and the wall unit is faulty and needs replacement.
HEADS UP Always disconnect power to the opener before working on the wiring. The low-voltage terminals are safe, but the main power line to the unit is 120V AC and can cause serious injury.