aharden

I replaced the 100mF caps with the Digikey ones that Habersham referenced yesterday and now my setup is hum-free. I'm thinking that the fact that the new caps are designed for higher heat levels and are smaller than the originals may prevent the issue from reoccuring. Thanks all for your help.

I was able to replace the two caps I mentioned, and I think things are better, but there's still noticable humming. I'm going to replace the two 100mF caps mentioned in this thread next.

I found this post pretty quickly from a Google search as the humming from my Promedia Ultra 5.1 system became too loud to enjoy the system any more. Thanks for all the info. In my case it appears that two capacitors on one of the amplifier boards (location labels C517 and C518) may be the culprit. They are the only ones exhibiting any physical signs of failure. I have a uploaded a picture of them here: http://www.flickr.com/photos/aharden/7125703883/. From reading the rest of this thread, it appears that the caps that most have replaced are the ones in locations C35/C36). I'm tempted to replace those as well, but I went ahead and ordered the 47mF/50V caps from Digi-Key similar to the ones referred to earlier in this thread. I went to Radio Shack first but they didn't have the caps I needed. I'll attempt the repair later this week assuming I get the parts in a few days. Thanks for all the information!