Thanks for your reply. Let me see if I can answer your questions with a bit more clarity:
1) Audible Hum: this was an "electronic" sound emanating from the back, not from the woofer itself. The Rel is in a corner, and I could hear it from the couch in the middle of the room when the room was silent.
2) Power: the blue power light light on the back panle of the sub comes on when the unit is plugged in. I turned off the Rel using the power switch in hope that it would "reset" and the hum would go away. When I turned it back on, the blue light was on, but no base was coming from the speaker, even when I turned up the volume of the woofer itself.
3) Fuse: I replaced the fuse thinking/hoping that this was the cause. The original fuse did not look to be blown, but I changed it, just in case.
I agree that it may be the sub's amp...just hoping that this is not the case. I am OK removing it myself, but what should I be looking for? Are there internal fuses that can be replaced?
thanks for your help!!