Denon Pre Amp no sound

Dealing with an issue in a recent post I bought a inexpensive pre amp to get me by until my equipment is repaired. I bought a PRA 1500 pre amp off of Ebay to mate up with my Denon POA 1500 amp. Anyway, of course, it came dorked up. One of the CD rca plugs were broken, but more importantly the small red light on the volume dial is not lit and the pre produces no sound. When something like this occurs is there one or two issues that typically cause the damage? And did I learn something from this experience, no more equip off of Ebay (again). I look forward to you thoughts. Thanks much, Dave