Sorry to suggest the obvious but have you tried calling either the dealer where you bought it or Paradigm's technical support number (available on their web site)?
Paradigm Reference, Signature 12 sub quit working
I have recently moved so it was necessary to take down my system. After being in storage in the original box and packing, the Paradigm refuses to come to life. I Have another much smaller sub which works perfectly, installed in the same position with the same cables, but nothing out of this one. Any ideas??