I’ve recently been without my PC for the past couple of weeks as I had a couple of problems with my old motherboard (Asus M2N) and so had it replaced with the newer model. Firstly, the sound would occasionally cut out and be replaced by pure white noise. The only solution was to reboot – sometimes I’d even have to open and close the tower before the sound would come back. Second issue was that I noticed that the left channel of my speakers had stopped working; I replaced the speakers to no avail. I then noticed that the front panel audio was fine – just the near audio was playing up.
I got my new motherboard this week, plugged it all in, and lo and behold – still the same problems! Eventually I tracked it down to the front panel cable on the tower itself – when I removed the cable and plugged the jumpers back onto the panel, sound works fine out of the rear panel – but I’ve lost front-panel audio/ microphone ability, which is annoying.