I have a 6 year old Maytag wide by side fridge model #MZD2768GE that is not staying cold enough. The bottom of the freezer is cold enough to freeze water and I am getting Ice build up but the top is very warm, the fridge keeps warming up as well. If I load it up with ice I can keep it cool enough to keep things from going bad. I would appreciate any ideas before I have to call in repairman.