Check the claw limit switches on the housing(?). There should be two, one where the claw meets the housing (telling when the claw is up) and the other near a torsion spring (telling when the claw hits bottom). Most likely something got unplugged, one or both of these microswitches are not working, or they are wired incorrectly. I hope this helps. Vending Junkie, BeTheClaw.com and a few others on YouTube have some good videos on repairing a claw machine.
Draco