No sound from the red rca channel on Node 3

I am getting output from only 1 channel ( the red one ) on my node 3. I know that the cables are good because they where connected to my computer to the same amp that I am installing the Node 3 on. My amp is a Peachtree Nova 300 and I'm not having any problem with any of my other equipment. I would appreciate any help you can give me at this time.