Re: No sound. The most common causes (aside from a control panel setting error) are bad capacitors (as JDW said, whether or not you can see leakage, they may have failed; just replace them -- it costs little time or money to do so), and a faulty audio output jack, in that order. To preclude the latter possibility, simply plug in a headphone and see if that works. If you get sound in the headphone, but not out of the speakers, the jack is almost certainly the problem. Cleaning the contacts or replacing the jack will fix it.