Buzzing from speaker...possible fix?

[murdoc]

I've got a set of M-Audio studio monitors model BX5a.  They are about 2 years old (out of warranty) and one of them developed a buzzing sound.  This buzzing sound is present whenever the speaker is powered on.  I've tried swapping power cables, and audio cables with the other speaker but it's still there.  If I turn up the volume I can drown it out, but when there is nothing playing (say between songs on a CD) the buzzing drives me crazy.  I don't know much about speakers, but is it possible to fix this?  I paid close to $400 for the pair and I'd hate to have to get rid of them if it was something simple like a loose solder connection or something.  Any help provided is appreciated.

[mhz40]

If the buzz is there even when the input is disconnected, it's likely a problem with the power supply... like a bad filter capacitor or cold solder connection as you suggested.  Often times supplies are generic and can be replaced as a whole part. You'd have to open the case, try to find a model number and do a web search.  In this case however, I'd guess that this is a custom supply.  Even if you bought it new from the factory, I doubt it would run more than $50.
If the buzz is only there when the audio input is connected, I'd suspect a ground loop.  To validate this, plugging both the speakers and pre-amp into the same AC receptacle would eliminate the buzz...

[murdoc]

If the buzz is there even when the input is disconnected, it's likely a problem with the power supply... like a bad filter capacitor or cold solder connection as you suggested.  Often times supplies are generic and can be replaced as a whole part. You'd have to open the case, try to find a model number and do a web search.  In this case however, I'd guess that this is a custom supply.  Even if you bought it new from the factory, I doubt it would run more than $50.
If the buzz is only there when the audio input is connected, I'd suspect a ground loop.  To validate this, plugging both the speakers and pre-amp into the same AC receptacle would eliminate the buzz...

Power supply huh?  I'll have to crack this thing open and take a look.  Ground loop idea is out, as it buzzes with just the AC power cable hooked up.  I've got them connected to my iMac via M-Audio Fast Track Pro.  The Fast Track Pro is powered by the USB, and the line-outs go one to each speaker.

[Nels Harvey]

The Fast Track Pro is powered by the USB, and the line-outs go one to each speaker.

Did you try to swap the line-outs to see if it moves to the other speaker?  That should narrow down the problem area.

Nels....

[murdoc]

Did you try to swap the line-outs to see if it moves to the other speaker?  That should narrow down the problem area.

Nels....

Yep, it stayed with the speaker.  I wasn't able to find any replacement parts online.  I called M-Audio and they will diagnose the problem for free.  They said replacement parts run from $5-$15 and labor would be $45.  I just have to pay shipping.  I can also get the diagnosis and order replacement parts and put them in myself.  I'm thinking this will be the easiest route.