Audience XLR interconnects not working

Noodlemonster, it is certainly a safe bet that none of the components in the OP's system or his friend's system are supplying phantom power to their XLR interfaces. We are not dealing with microphone amplifiers here.

Also, although I have a fair amount of experience with phantom powered professional microphones and mic amplifiers, I have no idea what you are talking about regarding "ghost signals," or when you refer to ghost signals being "180 degrees out of phase with the phantom signal." Phantom power is DC, and therefore has no phase, and is not an audio signal.

Or is your comment meant in jest?

Regards,
-- Al

As always, I'll second Peter's suggestion. And testing continuity is also a good idea.

I'll second Andirocks......
Most amps have a switch you need to use for either RCAs or XLRs......

From the Reference 110 Owners Manual it is a fully balanced topography with no switches for XLR vs Single Ended Input, confirmed via the pic of rear view.

Manual Reads as Follows:
Connections:
INPUT CONNECTOR: The Reference 110 uses a fully balanced circuit topology and has a pair of balanced XLR input connectors on the rear panel. It therefore requires a balanced preamplifier output, as provided by most Audio Research preamplifiers. Connect your preamplifier's output to the Reference 110 before turning on the amplifier.

Very odd indeed!

There is a slim chance it has to do with tolerances of the plugs and ports. I have encountered situations where a power cord didn't work with one product but did with all others. Similarly, I had an RCA interconnect once which would not fit onto a preamp, though it did with most. A very slight mismatch could spell a missed connection and silence.