Model #253.31619101, the complaint was the fresh food section was getting to warm, and then the customer noticed frost building up on the back of the freezer section. Frost free refrigerators utilize a defrost cycle to periodically remove the frost and ice that builds up on the evaporator during use. If the defrost cycle fails, the frost will continue to grow until it begins to block the air passages preventing cool air from flowing to the fresh food section causing it to warm, and if not attended to, the frost will begin to adhere to the rear cover. After removing the evaporator cover, I used a heat gun to start defrosting the evaporator so I could get access to the element and bi-metal thermostat. I found one of the connectors to the element was loose, so I manually started a defrost cycle, and then used my meter to verify voltage was present. I read 120vac so I new everything else was working. Cleaned and defrosted the rest of the evaporator, repaired the connector, and now this unit can defrost itself.