Do what Adrian said by swapping a known good cable. Then do what I said by putting a channel (eg. Right channel) into the center input of the ADA and seeing if it plays. If it does, the ADA is ok and that channel on the receiver is bad.
A-LFR/1000-8/500v4x2 coming
100,160,QS10x2,800,M5,M3,M50 v4
had v2
Air N2 (someday)