volume and rec knobs not working

yea i turn them all the way up and they are at the same volume

any explaination or solution to fix the problem?

already took the knobs off and tried turning the pins...same result

The fact, that when you have these knobs turned all the way to the right, there's no sound coming into or out of the mpc doesn't mean that they are broken. First, check your mixer and master settings. Maybe you have these turned down.