Good news! I found the solder jumper and removed it this evening. Put things back together and I'm once again listening to music from my Rotel as we speak! I even picked one of my scratched up discs and it seems to be happy so far. It's too soon to call it a success, but things are looking good so far! I will probably still put the new ribbon cable in there when that comes too, since I've had the original one out a couple times.
Since I did pick up a budget replacement which will also so SACD and DVD-A, I'm interested in doing a more critical comparison between the two, now that this one is working again.
Thanks again for the tips, I would have probably given up on the broken Rotel without your suggestions.