If you have tried all other recommended solutions, (the hose is clear, and you hear the pump powering on, and the coin trap is clear), check that the pump impeller has not broken free. Pull the impeller out from the pump, and check that the magnetic shaft and impeller do not spin separately. If they are not solid, the motor will spin without delivering torque to the impeller. Testing on a workbench may show the impeller spinning, until the impeller undergoes a load, where it will stall. If you can get a replacement impeller and shaft, that is all you need, else replace the whole drain pump.