Solved! hum from mixer

[lumens00]

Hi guys new to the forum here. I have an Alessis Multimix 8 USB that is having a humming/buzzing sound even when nothing is connected while listening on headphones or pc. I can get the hum to lower by increasing the volume on line 3 while listening on line 1. Not sure if ground loop, I've tried using a different power supply and on a different wallplug. I currently have it opened up to see if I can figure something out. Anyone here have a similar experience and solutions? Thanks

 

[COLGeek]

I experienced similar issues in the past when connected to power with a poor ground. Does this issue occur all the time, via all outlets?

 

[lumens00]

I experienced similar issues in the past when connected to power with a poor ground. Does this issue occur all the time, via all outlets?

I've only tried it on 2 outlets with ups and 2 without+power strip. It has humming on all of them. The power brick doesn't have a ground prong but it works fine on another mixer.

 

[lumens00]

Problem has been solved. I found 2 browned capacitors on the power supply cct and tried replacing them which did the trick.

 

[COLGeek]

Problem has been solved. I found 2 browned capacitors on the power supply cct and tried replacing them which did the trick.

Glad you sorted it out. Well done.