The actuator has a notched silver position dial. Does it turn smoothly when the dash dial is adjusted?
If motion is jerky, not through the full range or if it makes a gravel or ratcheting sound, the gears inside are likely broken. Ignition off, remove the actuator and verify that the three dampers move. If they do, you can open the actuator up to check the gears, but it’s probably shot.
If no movement (or sound) at all from the actuator, disconnect the wiring connector and it should have three wires. I forget the colors, but one is battery voltage, one ground and the other the signal from the panel which varies (I think 1 to 5V?) based on dial position. Check all three for voltage/ground. If no signal from the panel and no wiring damage, the panel would then be the culprit.
If electrical checks out, verify damper movement and actuator gear condition.