Just pickup up this used fridge. Looks great but of course I found out the hard way that the water dispenser doesn't work. I know the water line from the house is good because I swapped it from another fridge where the water worked. The manual says I can run the water without a filter so I tried removing it with no change. I can see the water line running into the door and there's a bubble in there that doesn't move when I hit the water switch so i assume its something before the line in the door. The fridge was sitting for 3 days inside so I don't think it could be a frozen line. Where should I start troubleshooting?