The "Main" button does not work

Ok,
Just got back on mt mpc after two weeks and the "main " button stop working after 1hr. of use. I only have the reg. software not jjos, so I basically I can't make beats. The button still click down just does not go to screen. Any Ideas?

Try factory reset ,hold down erase when powering if not its cabbaged.This happened to me i was devastated but got over it.I MOVED ON

I use JJOS2 and every once and I great while it stops working. I usually just push it about 3 times before it gets back to working as usual or I have to reboot the MPC.