Hi, I have a Gemini 676pro mixer, please don't laugh, I know it's old, but this mixer has given me years of trouble free mixing. However, this morning when I turned on, I have this buzzing noise coming from the right channel, it seems to be on the output side of the mixer as I have unplugged everything and the buzz is still there. Also I have noted that two of the power meter l.e.d's on the right channel are lit which suggests the hum. Does anyone have any idea what may be the cause of the problem? I am pretty good with a soldering iron so if I need to change any components I'm sure I will be able to do it. I just need an idea where to start looking.

Thanks in advance.