Help w/ MPC500

I am having trouble getting any samples to play. I have pressed (mode) and (load) and loaded up a set of samples, but nothing plays when I hit the pads, although I can play the full song. And the pads respond to everything else (i.e. loading samples and such), they just don't play sounds. My fader is up, both volume at app. 70% (although tried in all levels), and still nothing. Please help, I have used MPCs for a while now but haven't had to set one up, and have exhausted almost every word in the manual to no avail.

Ok, well, as Murphy's Law works, as soon as I posted this, my MPC decided to start playing samples. What a little diva.