Ice & Ice Cream would melt and refreeze

Noticed the problem in November 2009. Replaced Hi Limit Sesor for Defrost thinking it was the freezor temperature sensor. Did not fix the problem. Replaced Motherboard. Did not fix the problem. Called Sears Repair. They mis-diagnosed the problem and told me it was the sealed system. I doubted them and sent them home. Replaced the correct freezer temperature sensor that connects to the motherboard. FIXED.
Removed a panel, cut two wires, soldered and insulated two wries, reinstalled panel.