mpc 1k mute problem and yamaha problem

hi im useing jjos 1 and im haveing nlittle problem with the mute function.
Problem im haveing is dat when i mute pad it comes back on automaticly when i press play
why?? how i fix it???

Also if anyone useing yamaha mo8 or 6 i need some help
the faders move at same time ex i move fader 2 and it moves fader 1&2 on the screen
i called yamaha they said might be dust but i only had keyboard for week
the faders only do it sometimes. anyone know how fix it??

appreciate it