I have an igloo 102st countertop ice maker that has stopped making ice. Everything on the unit is operational, but the freeze tray will not stay in the raised position when it is time for the water to be pumped into it. The tray does lift, but then it goes back down, then the pump runs but all of the water just runs back in to the reservoir. How can I get it to keep the freeze tray in the proper position again? Thank you!