Equipment:

Yamaha RVX-640 receiver

Klipsch reference series speakers

Mitsubishi DD8040 DVD player

DirecTV H20 HD Sat Receiver

This past Friday night we had a BIG BIG lightning storm ........ lasted for hours. Zapped my original DirecTV HD receiver and a phone hub. So DTV sent me a new receiver and everything works fine ........... except

Everytime I change channels with the HD receiver or switch tracks on the DVD player I get a "thump" in the sub-woofer. It does this whether I change channels or tracks with the remotes, or manually with the buttons on the DVD player or HD receiver. Other than that the sub and all the other speakers work fine.

Since this occurs with either the DVD player or the HD receiver I'm thinking the problem is with the Yamaha ...... or possible the coaxial cable to the sub-woofer. Anybody have any clues? Or any suggestions on anything to try to narrow down my search. Thanks