I have a Rythmik F12 which I bought from Ascend back in 2010. It recently started making a fairly loud humming noise. I've followed the usual troubleshooting steps. It is present both with no RCA signal input and a grounded input. It is not present when the power switch is turned off. It is present on multiple circuits in the house, and regardless of what else (or nothing) is plugged into that circuit. I have another Rythmik subwoofer in another part of the house that is still working fine so I don't believe it's anything in my house power that has changed.
Opening up the subwoofer, I took a look at the amplifier and found that two of the 6800 uF power supply caps were bulging, with one having obvious signs of leakage. The caps were disappointingly low quality ones from JunFu, which have what seems to be a unique form factor with a 30mm diameter. I was not able to find a replacement with the same form factor, but I got 35 mm diameter replacements from Digikey manufactured by Cornell Dubilier, part #380LX682M100A052. These fit with a little encouragement, and the hum seemed to be gone for several days. Unfortunately, it has now returned and I'm not sure where to go next for troubleshooting, there weren't any other components that showed obvious signs of failure. I submitted a request form to Rythmik several days ago and haven't gotten a response yet. Any recommendations for next steps?
