Repair service for Revel B15 subwoofer

I have an old B 15 subwoofer that I use as a center channel bass source with my home theater system which is otherwise very modest. I have noticed lately that the woofer is not putting out sound in response to an input signal. The woofer itself seems to be OK. I believe the problem is with the electronics. Does anyone know a service or a shop that has some expertise in repairing the electronic components of this unit? Thanks for any response.