My DSL cable makes my computers buzz

Last night I unplugged my DSL from my desktop and plugged it into my laptop. As I was puttering on my laptop, I noticed a strange intermittant buzz–just a quick “bdddd” every few seconds. My laptop had never made this noise before, and I was afraid a fan was starting to hit something or something.

This morning I put the DSL cable back into my desktop, and as I was puttering around on my desktop, I heard the buzzing again. This time it was coming from my desktop. It sounded much quieter. I didn’t think the desktop had been making that noise before. To be sure, I started up my laptop with no DSL cable, and sure enough, my laptop wasn’t buzzing. It was my desktop.

Here’s the really strange thing. The sound is hard to locate because it’s so bass-y and so quiet, but as far as I can tell, it’s coming from my speakers.

Basically, my question is WTF.


Ground loop.

I guess I’ll go google that or something… :rolleyes:


I am not sure that it’s a ground loop problem, since my buzz comes in short, regular bursts and mains hum is typically a constant sound.


What our unhelpful friend means is that you may have a circuit loop formed when you have multiple paths to ground from various pieces of equipment and also shared ground connections between pieces of equipment. Sometimes this is easy to fix by simply breaking one or more interconnected grounds, or by ensuring there is only a single path to ground. Other times, it’s not quite so simple and you have to look to things like isolation transformers or ground-loop filters to solve the problem. Because things like audio and video cables have a grounded shield around them, ground loops are particularly common with these types of setups. Knowing this, see if you can eliminate or reduce the problem by disconnecting various interconnects; once you’ve found one, you can start to determine the best solution for a more permanent fix.

Ground loops don’t always result in mains hum. A ground loop is essentially an antenna; it can pick up all sorts of electrical noise depending on how long it is and the various impedances presented in the equipment.

I get that too. But the cause turned out to be my cell phone.

Whenever the cell phone is within a short distance of my computer the computer speakers emit an occasional clicking/buzzing sound. The phone isn’t in use with a call its just on and available to receive calls

I think its caused by some locating/handshaking between the phone and the nearest cell tower.

I mention this on the remote possibility that your cell phone may be close by during those times when your computers buzzed and the dsl connection is a coincidence.