no sound when playing sequences in my MPC 60

ok folks....

here is my situation:

i sampled some drum hits on pads perc1 and perc2. when i record, i am able to hear the metronome and the pads play fine as i lay down the sequence. yet, when i do a playback, nothing was recorded as there is no sound coming form the MPC!!

any help on this would be much appreciated peeps.

pce.