HELP: No sounds out of my tweeter.

I own BW800 Diamond. I just bought a used pair of interconnect to use from my pre to amp. When I hooked them up I HEARD A LOUD EAR PIERCING HUM OUT OF MY RIGHT SPEAKER. I immediatly turned off my system. I then put my old cables back on and the hum was gone.

Now the diamond tweeter out of the right speaker is no longer working. Do you think it's the xover or the tweeter that got fried. What do you think caused this? Is this easy to fix? If the problem was caused by the interconnect. Should I hold the seller of the IC responsible?
A used pair of interconnects could be returned for a refund, but the problem created by them is yours and yours alone.
If they were new and from an authorised dealer, it would be different, but used the buyer has no rights.
As to the speaker, the diamond tweeter is going to be very, very expensive to replace, unless B&W can recoil the tweeter you have. You destroyed the tweeter, not the crossover, unless the crossover has a fuse that can be replaced. Call your dealer.
Sorry that this happened to you.. I own some B&W 805s.
Was the system powered down when you changed interconnects?
The system should have been off when you connected the cable. Then slowly introduce volume. If the cable is bad you won't be able to get any recourse since the problem may have happened after it was shipped or given to you. Are you sure they were both properly seated into the power amp? Why kind of cable with what kind of RCA connector on it? It would take the positive side only with neither the left or right ground present for this to happen unless you have monoblocks or dual mono design without common ground between the left and right channel. Sorry the tweeter was roasted. Good luck.