My Cary SLP-05 volume control does not work

Check switches like the bypass/loop switch?

DeKay

I think @viridian nailed it. 

Do the two balance volume pots change the output?  It would be unusual for both the main and  the two balance pots to not work.  

This may or may not be related but I had a Cary SLP-03 preamp and the volume control from both the unit and the remote control stopped working as well as would do the opposite when trying to raise or lower the volume from either place. My buddy had the same preamp and the volume would not work at all after he had it unplugged for few months. In both cases they had to be sent back to Cary for new volume pots, they said they were "mistracking" and needed replacement. I also had to send mine back twice for the same problem.

 My preamp has been boxed for 3 years and when I hooked it up there is volume to the speakers but the volume control does nothing to raise or lower the volume and the remote does nothing. An ideas?