pyellman

Thank you very much for the input. I have to think the thought about the fused transistor or FET is on the mark. Maybe I'll check the voltage on that output for grins. I guess I will be bidding on that used amp, but laughing at myself at the same time -- if I replace that, I'll have replaced everything but the the left satellite! Still be cheaper and better than the garbage Logitech system I just sent back.

Replying to my own post to add some information. First of all, I know almost nothing about this stuff, I'd just like to rescue my ProMedia 2.1 system if possible, so please bear with me. On further analysis, it looks like the voice coil is pretty cooked (see attachment). It took me a while to recognize this as the voice coil, I expected something bigger from looking at pics on the internet. I guess the burning/smoke was the voice coil and adhesive. Looking around, there are some opinions on the implications of a burnt voice coil, such as at sound.westhost.com/articles/speaker-failure.html#s7. According to this, discolouration in the middle or all over the coil indicates that the coil was "driven with too much audio power for too long". I almost never turned these speakers up past about 1/3 of the way, even accounting for Windows volume control. In fact, at the time of the burnout, my daughter was listening through headphones attached to that speaker, there was no sound coming out at all. Other sources blame "pure overpower", or a power surge for a fried coil. I have read that this system has fuses protecting both channels, but I have been unable to locate such a fuse on my model. Inside my subwoofer/amp I only see one fuse labeled "Fuse 1", and it looks nothing like the kind of replaceable fuse that is shown for this system in other posts on this forum (mine is square/grey-black). Here's a nice video of a speaker/coil being driven to the point of flameout youtube.com/watch?v=KErbjC98yoM. I will note that my speaker would begin to smoke almost immediately when powered up through the subwoofer/amp, without any movement at all. I've got a used ProMedia 2.1 satellite speaker coming in the mail, and I plan to harvest the mid-bass and put it in my satellite (which is also the control pod). I would like to hear if anyone has suggestions on how to test the other components, either in the amp or the satellite, to determine if they might be the source of the problem. As I said, a visual inspection reveals nothing, in fact everthing else is quite pristine. I want to feel safe leaving this speaker plugged in to the amp!

I have a ProMedia 2.1 system, about 5 years old. The other day, I noticed the right satellite speaker was buzzing/humming pretty bad, and when I got closer, I could smell burning. I unplugged the system of course. Today, I took apart the satellite, and also took the back panel off the subwoofer/amplifier. There was no visible damage of any kind to the subwoofer/amp, it actually seems to be in very good shape. So, with the cover off the satellite so I could see exactly where the smoke might be coming from, I plugged the system back in and powered it up. Smoke immediately began coming from the mid-bass on the the satellite; it seems to be the cardboard-like part of the cone that is burning. It seems like a genuine fire hazard. Other than that, the components of the satellite speaker also seem to be in fine shape, including the braided wire that attaches to the cone. I'd be interested in hearing any theories on what might be the cause of the failure of the satellite, and whether it would be risky to attach a different (purchased used on Ebay, for example) satellite speaker to the right channel. Thanks for any thoughts.