Pads play no more sounds ?!

Hello,
my MP500 plays no more sounds when i push the pads.
I can load the samples and the programms and the mpc plays already saved sequences, but the pads are silent^^.
I checked everything and really don't know what the problem is.
It was from one day to the other...

It would be great if someone could help me.

Did you even used search before you posted?

viewtopic.php?f=26&t=107142

Yes i did, but that is not the solution.
The mpc loads the samples and the programms (and the sample are assigned), but they were not played on the pads.

mode+midi/sync
Pad to sampler -> ON

Thanks a lot !!!!!! It works ...