It's kinda hard to explain the problem. I have 2 old speakers that I plug into my AMP unit and then into my pc. After a while the speakers started to randomly buzz, stop working, then work again. But never both at the same time, either the right one or the left one. Recently I upgraded my pc completely, and I also got new speakers. Cerwin Vega ve 5m. And guess what, it's still happening. Then I changed all the cables, for the speakers and also for the amp/pc connection. And it's STILL happening. Any advice? Its really hard to explain how they start buzzing, it sounds more like tearing up or breaking up. Or they just stop completely.
You've ruled out most possibilities. All that seems left is that the amp is bad or the output jack from PC is bad (since you have ruled out the cable in between by replacing it). Are you using the green 3.5mm audio out on the computer? Can you plug headphones in there instead and see what they do?
It's not that. My motherboard is 3 weeks old. I just upgraded all of my pc components. ANd this also happened with my old mobo. I just don't get it. I will take my AMP to the shop tomorrow to try and get it "fixed" but it worked fine when I took it to my friend's place to test it.