my pads on the mpc2000xl aren't working....

someone please help, i am a newbie with the mp, and i am able to make beats and everything on it, but my pads aren't working, only half of the pads r working (the 8 to the right are working, the 8 to the left are not working) someone told me there is a program i could run inside the mp to test it out......and see what the problem is......can someone please tell me how to access this program, i think he said something like hold down shift and restart the mp, but that ain't working for me...........


thanks for your help in advance...........

Try the PAD TEST trick

SHIFT 5 (Trim)
SHIFT F1
F5
F5
Put on Full Level

Now go through you pads pressing (hold down for 2secs) each one ofem for a response.......
Each pad should show a value of 127 for both Velocity & After Touch