I can't get any sound out of my Sony SW-WM40 subwoofer and I am trying to diagnose the problem (is it the the speaker, the cable, or the receiver?). The speaker was working fine earlier today, but I switched the cable to my H/K 310 receiver since the cable I was using was too long. At that point the speaker stopped making any sound, although it would sound intermittently if I jiggled the cable around. Assuming the cable was defective, I switched back to the longer cable, and from then on I can't get any sound out of the speaker using either cable. I am assuming that the cable is not the problem b/c I have two that don't work. Also, when I plug one end of the cable into the subwoofer, turn the volume up and tap on the other end of the cable, the tapping doesn't cause the speaker to make any sound at all. That makes me think the problem is with the speaker. Is there anything else I might do to confirm where the problem is so that I know what to fix? Any ideas on what may have caused this to happen? Many thanks.