are you talking about LOOP function as like ont eh other MPC models.. where when in sequncnce mode you hold down that specifric pad and itll loop the sample till you release it??? well shit.. to be honest ive had my 1000 for months now and havent figured out how to do it... I know how to do it on my 2000 and other models.
or you just talking about looping the sample so it loops clean?
if so just keep messing with the strat and end times till you it got it down like butter... when in the trim mode, make sure loop is on and hold down the pad and keep adjusting the start n end times till it loops proper.. feel me?