No power supply to my Aqualisa Aquastream Shower?

Hi. I installed an aqualisa aquastream shower about 8 years ago. The front knob became detached a good while back and I replaced it after a time. However, the threads it attached to were damaged, and it remained uncovered. Now there is no power to the water supply and I wondered if anyone can tell me if perhaps the motor is gone, pump etc and if there is any way to fix it. Or does it need total replacement. Thanking you in advance
Kathleen