On 10/31/05 12:16 ET, Ernie Bornn-Gilman said...
Weird thing --
it hummed with the source disconnected. Then
it hummed with the POWER disconnected. Turned
out it was his refrigerator on the other side
of the wall, and because he had just gotten a
sub and mentally tuned in to that low bass, he
suddenly heard the refrigerator, which had been
humming like that for seven years.
Nice trouble shooting technique!
Reminds me of when I installed some 2m and 70cm Ham Radio Antennas for Satellite. In the next week I had 4 neighbors complain that I was destroying their TV reception. That was quite the trick, as I hadn't even connected the antennas to a transmitter yet!