What are your thoughts?,
I've had issues with my KRK rokit 8s where a popping sound would sporadically occur on top of playback. I found out my issue was the drivers on the main board, which thankfully I was able to fix myself by ordering a new board for 90 bucks and simply unscrewing and replacing a couple things (I am by no means a DYI guru). With that said, I'm not sure your issue is with the drivers, as it's a slightly different intermittent fault.
I would try KRK's troubleshooting steps for 'no sound' if you haven't already: http://www.krksys.com/krk-trouble-shooting.html
[ Post last edited on 10/06/2014 at 04:19:59 ]