MPC-60 plays random sounds - Help!

Newbie on the list, but I've had my trusty MPC-60 for 14 years. I fired it up today, loaded my custom Live Set, and now it plays random drum sounds all on it's own.

I had this once before if I had any midi-in signals while loading the drum set. I have disconnected all midi in and out and I still get it.

Thanks

Steve