I purchased a ddj-sx about a month ago and it has been working great. Heck, it even worked yesterday.
Today I plugged it in and got ready to go, but when I tried to play music no sound would come out. The individual channel LEDs all light up indicating sound, but the master LEDs stay dark and no sound comes through my master output 2. I have tried turning on and off the controller so I know the master LEDs are not broken. all volume knobs and faders are maxed. It looks like I have the same problem as this guy (http://forums.pioneerdj.com/entries/22804651--CLOSED-Problem-No-Audio-Output-on-DDJ-SX-with-Dell-Laptop), but no one ever figured what was wrong with his.
That was 10 mins ago. Now I reinstalled the ddj-sx drivers and firmware straight from Pioneer's website and for some unknown reason my laptop can no longer even recognize my ddj-sx. I have restarted my computer and the controller and still nothing. I'm using a custom computer from iBuypower.com running windows 8.