There isn't a fiddly little knob on my Toshiba Satellite C655 laptop... (other posts had similar issue and said knob was the fix) and all the settings are as they should be, I believe. Just found out that my son DROPPED it a little while ago. Is it possible that he could've jarred/damaged the sound card or something? The sound I'm getting can be forced loud but is distorted and sounds like its filtered. (vocals almost absent, blaring highs and treble, hollow and empty sounding) Hoping not to have to take it to Geek Squad... Anyone???