How old is the MPC? Check with Akai to see if they will replace the whole unit, or repair it under warranty first. Sometimes companies will cover things you wouldn't expect unless you take the time to ask them, and sometimes they will do it after your warranty has expired.
I had a 4 year old Yamaha CD player that crapped out in college. I called Yamaha and they replaced it with a current production unit for the cost of shipping the old one back. My 9 month old iPod got replaced with a brand new one when I took it in to the apple store, it got replaced because the 'click' button didn't click. The thing looked like it was raped with a belt sander....Twice. I didn't even ask for a replacement but got one anyway because the unit wasn't up to spec out of the box.
Plus it gives you a chance to start a relationship with Akai. Something I think a lot of people overlook, you are paying them to support their product, make use of it.
You'll find if you are reasonable, most of the time they (companies in general) will go out of their way to make their customers happy. This has been true with all the software and hardware companies I've dealt with for numerous years. Except for Autodesk, whose service is kind of meh... I wish Alias|Wavefront didn't sell out to them.
