So I picked up a used JD 155LT last week and was playing around with it and seem to have gotten the mowing deck locked where it no longer moves up and down. The deck appears to be in the up position. The deck lift handle locks forward and when I depress the button I can move the deck lift handle backwards, but it doesn't lock in the back position or move the deck (there's no tension on it when I am moving the handle). Is there a release button I'm missing or did a spring pop off? I'm waiting for the manuals to arrive in the mail so I can check the diagrams and should get them on Monday, but thought maybe I should just jack it up and take a look. Is there something simple I could be missing? Thanks for your help!