I bought the sony rcvr recently and worked fine for a week or two but then all of a sudden the recvr. fails to emit any sound from the sub. I even tried going thru the test-tone menu but all the other spkrs pass the test tone test but nothing comes out of the subwoofer. dunno why ? what caused it ? may be the settings ? i went thru the manual, tried every possible setting but no result... Took it to the sony service depot, they were not helpful at all instead had a big yellow sticky posted on the box saying: please follow the instructions in the manual, no fault found but won't specify what settings to use or what may have caused the subwoofer to go quite. i would really appreciate everybody's input on this. p.s. i'm using regular rca audio cables for connections. thx