Nordost Frey interconnect hum


I bought a pair of used Nordost Frey unbalanced interconnects here and i noticed they induce a hum through my speakers when my preamp is off or when the cables are only plugged into the power amp. The strange thing to me is that my Nordost Heimdall interconnects do not induce the hum under the same conditions nor do other shielded interconnects. They do the same thing on another system as well. I understand that both the Heimdall and Frey have the same 97% shielding and the only difference is 2 extra center conductors. I'm waiting for the seller to ask Nordost but i thought i would ask here if anyone can explain it.

Thanks for any advice.
pongagt
Thank You very much for all the replies. I really appreciate it. I checked the ground tabs during a visual inspection right after i received the cables and they look fine. The solder joints looked ok as did resistance checks on the cables. I also tried installing them in a reverse direction and i am sure they were very tight. I use Deoxit on all the connections. The jacks on my amp are only a few months old. Like i mentioned, there is no hum with any other cable i use. What makes matters weirder is that both cables have the problem. I'm going to call Nordost tomorrow. The two that might be able to figure out if there is a problem were at the CES last week. I'm hoping the seller will take care of the problem if there is something wrong with the cables but he has been unresponsive recently.
Pongagt, unless the cables prove to be defective, the seller has fulfilled his obligation.

Nordost is an excellent company and has excellent customer service. Good luck.
sounds like a ground loop - I had that on a particular cable and was not able to solve it. It was a preamp to amp connection.
The cables are defective and Nordost is going to rma them in this case. The shields probably got disconnected some how and that problem will not be evident by a resistance check since the shield is only connected on one end and there is a negative wire that connects the ground tabs on the WBT connectors. I don't know what happened to them or what the seller knew but Brf is right about Nordost. Thanks again for all the help.

I did not get the hum with any other cables so there is no problem with my equipment.
Nordost "gets" customer service. A simple fix, no extra charge, no hassle, and they gain a customer for life.