MPC NO SOUND PROBLEM PLZZ HELP

so i was messing around with an old yamaha keyboard and i plugged it into my mpc via midi

i played it a lil, then i decided to load some drums

i loaded the drums and when i pressed the pad i heard no sound, i checked EVERYTHING

i dont know WHY but my mpc refuses to play any sound in any mode

it only plays the samples in the load moad to preview the sounds

i checked everything

i cant get any sound out of my mixer, somone pleaseeee help me