Connection troubles...

[jducoeur]

Okay, I'm looking for some ideas here, because I clearly don't understand quite what I'm doing.

We're trying to run some videos from msmemory's laptop to the TV system. (Watching Torchwood.) The video side was easy, once we realized that she has an S-Video output, which I could hook into the DVR. But the audio is being a hassle.

The only audio output from the computer is the headphone out. Okay -- I've got several headphone-to-RCA adaptor cables, so I used that to plug it in. Which works -- but it's got a persistent annoying hum, very much like an ungrounded turntable. It's not the cable doing it: I tried several cables, and they all have the same effect. It's not the DVR: plugging the same cables directly into the receiver has the same hum. And I don't *think* it's the computer, since plugging in real headphones doesn't seem to have the same effect. (Although I haven't conclusively ruled out that possibility yet.)

Am I missing something here? Is there something wrong with the idea of using such an adaptor to go from the computer to the A/V equipment? It's not preventing us from watching, but it's a bloody irritant...

Comments

[dlevey.livejournal.com]

I've run across am odd hum going from the laptop to the stereo. I eventually traced it to a nearby cellphone, with periodic checks to the nearest tower. From what I can tell, the cordless phones (2.4GHz) produce a different but also noticeable hum. I don't know why headphones don't do this also, unless they do but the hum isn't being amplified as it is through the stereo.

[jducoeur]

See the later comments in this thread. Our problem turned out to be asynchrony between the power outlets -- unplugging the laptop fixes the problem...