Okay, so the RDC I got off eBay came today. I installed it, but just like the old one, it doesn't even show up in INPA and is shown in red in ISTA+. I tried doing the reset anyway, but it just gives me an error message, which apparently translates to "SG not connected or does not answer RDCKWP". I've already checked for power and ground at the RDC, but not sure how to check the twisted pair. Anybody have any suggestions besides the obvious "ditch the eBay part, buy a brand new RDC and try again"?