RMX is back in service with a battery change

However our 15-80 is most perplexing. PSU is fine and the unit functions but I am trying to isolate why my channel B output is acting funny.
(with output switch set to mixed)
1.Channel A input pot raised, I get audio on both outputs. The audio has random spurts of digital nose.
2.Channel B input pot raised with Channel A input raised does not effect anything on the outputs. They stay as in #1
3.Channel A pot lowered to infinity and I have no audio at the output
4.Channel B pot is raised with channel pot lowered to infinity and I have no audio at the output as in step 3
I can repeat and get the same results regardless of input switch set to mixed or individual
(With output switch set to individual)
A. Channel A and B input pots both raised, I do not get audio on the channel B output, just random bursts of audio +noise
B.with input switch mixed I get the same results as in step A.
I have swapped the input cards and the DAC cards around, there was no change.
I am leaning towards a problem on the ADC card. But still doing further testing.