I picked up two pr. of JBL 940's. One pr. is mint. The other pr. has one speaker with the 8" and 10" woofers not working. Both drivers move in and out without any VC rub or friction. When I try to power the speakers-nothing happens. No movement or sound. No apparent damage. What might the problem be? Could the VC be fried and still no friction? To replace them both is too much $-about $180 for both and they are not high quality drivers. I could rebuild them but i have yet to find the kits... Any thoughts?