Volume knob Not working to raise Volume

Volume knob Not working to raise Volume

So the when I turn the Volume knob up to increase the Volume it just goes down to negatives(ex….-1,-2,-3etc..)and I cannot get it past the 0 to raise it just goes into the negatives. The knob spins all the way around when it suppose to go up to 12oclock(+) and down to 6oclock (-) . I took it off try to push it in but cannot figure… Does anyone know how I can fix it??

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