Need help finding a hum problem


I just got a new TT (Elipson) and hooked it up to my Counterpoint SA-7.1 pre-amp.  It's the first time I've used the RIAA stage in ~26 years, and the first time since I sent it in to Counterpoint for conversion to SA-7.1.

When I set the pre amp to RIAA input, I get this hum from the right channel.  Left channel is fine, and it is not a case of ground loop.  I swapped the tubes just to be sure and the hum remains in the right channel. 

I understand Counterpoint used a bad batch of capacitors at one time so I presume its one of these.  Question is, identifying which one.  Any helpful points or hints here?

There was a problem with the a stage capacitor but this was easy to spot: a very obvious leak.  That was replaced and the line stage works fine.
zneret
Looks like it is the turntable connector cable (double RCA).  The other connection on one cable has no continuity. 

There's a residual hum but that is because the Ortofon OM10 is MM cartridge while my SA-7.1 is tuned/designed for MC.  Looks like I need t get myself a MC cartridge now.
Never mind.  Appears to be a TT issue.  Swapped in another amp and same issue.  RIAA stage is silent with nothing attached.