I posted this message a few months ago, and wanted to try again, since I got only one response.
I watch movies on my computer. I have 2 S-video cables (connected with a coupler), and a 20 ft. 1/8" headphone cable (with a 1/8" - 2 RCA adapter) running from my computer to my DVD burner. I then have component video cables coming out of the DVD recorder going into the tv, and then fiber optic cable connecting the DVD recorder to my amplifier.
What happens is that when I watch a movie on my TV, I have to turn on my DVD recorder first (out of inputs on the TV), then turn on the amplifier. I get an electrical hum, which ranges from "mildly annoying" to "downright maddening" in the background. This probably means I'm turning up the amplifier too loud, but if I turn it down, you can't hear it.
Troubleshooting: When I unplug the headphone cable from my computer, the humming stops. If I plug it into a portable CD player, it's still gone, so therefore it must be coming from the computer. Another member suggested it could be the sound card, but mine is integrated on the motherboard, but how do I test or fix that? The computer is plugged into a surge/battery backup. Could that be it?
Thanks in advance!