I'm hoping someone can point me in the right direction. I have basic (very basic) skills with soldering iron, multi-meter, etc. My Powerblock has developed a bothersome bit of distortion that is always present even on the cleanest settings and at all volumes. Obviously it's harder to hear at low volumes but if I listen carefully I'm sure it's there. Where would I start looking for the problem? Is there one typical source for such or are there many? It's not worth paying somebody to look at it. That would quickly go beyond it's $ value. But I'd like to learn something more and this seems like a good place to start. And keep it out of the landfill. What would be the first one or two things I should check? Thanks.