Sometimes when the hinge block is frozen it is due to swelled pot metal. First I remove the screw and polish it, then I polish the inside of the pot metal body. I use synthetic oil so it will not gum up again as many times the old oil is the problem, especially on DD reproducers.
With the screw tight the hinge block should move freely, but sometimes due to swelling the screw will be too short. To better understand how important the hinge block is look at a DD reproducer when it is playing, the limit pin moves up and down and back and forth.
