I just inherited this Fridge. Original owner took very good care of it, but said he had never hooked up the ice maker. Back of fridge ice maker hook-ups look ready-to-go: water line in place above water inlet hookup. I know our water supply works because I just removed previous fridge with working ice maker. But with water supply hooked up to this "new"/old fridge, there is no water going thru the unit's plastic water tube on back of fridge = no ice. Hope you can help me get ice maker working. Thanks very much.