In case you couldn't tell by the title, I don't really have any idea what I'm doing with electronics. Something happened though, and I am really curious about it. Don't know how to ask it specifically, so here's the backstory.
I brought out some old speakers from storage. I plugged them in, and they didn't work. However, if I turned, twisted, and pulled the volume turner just right, the speakers would start working. Usually only one worked, and the other was staticy, but which one was working would switch back and forth. After using them like that for about a month, I decided I had enough and took it apart to see if there was a loose part with the volume knob. Everything was soldered down tight, and nothing was loose with the knob. With everything on, I poked around at the soldered points with my screwdriver and heard some loud pops from the speakers. Just like that, they started working again (not perfectly, but 100x better).
This leads to a few questions. Why does poking at soldered points make them work again? Does static build up overtime or something? Also, is this dangerous to do again? The screwdriver is insulated, and I'm not touching any metal with either hand, so why is there any effect at all?
The speakers started acting up again recently, and the same solution worked once more.