What happened?

So I was DJing a couple weeks ago, everything was good, the floor was starting to fill, the energy level was going up just at the right time, and all of a sudden, silence. not good. I use Serato, and noticed first that I wasn't getting any sound with the song I was trying to cue up, then about a minute later, the song that was actually playing on the other channel cut out as well. My CDJs were running fine, the Serato box was still lit up, and I had my dual screen, so I know things were operating normally, there just wasn't any sound going into the mixer. When I switched the cables to the "Through" settings (to bypass the Serato box) and played normal CDs, everything played fine. After the gig, I let things sit for a couple days, and hooked everything back up, and it has worked normally ever since. I'm happy it's working again, but also paranoid that this problem could come back, and I can't figure out what the problem was. Anybody have this happen to them?? Any ideas as to what the problem was?