Analogue systems

hello all, I just joined the group. I just bought a Doepfer rack and 
am trying to use an AS RS500e filter module, I get no sound out of it 
at all. I have the saw output of a Wiard VCO going to the signal in 
of the RS500e...nothing. I can turn the res up all the way and still 
nothing. Looks like the ribbon cables are plugged in right. I have 
tried running the signal out to a VCA, and straight into my mixer, no 
change. Any ideas?

Thanks,

RSA