Aaron B Blaine , WA July 27, 2016 Appliance: Model LFX23965ST Error code er ff Unplugged the refrigerator, Disassembled the freezer's racks, rails and unscrewed the back panel opened the access panel. Replaced faulty evaporator fan motor, Defrost thermostat and Hester Sheat of evaporator unit. Installed back the back panel and screw in the rack's rails, Plugged in the refrigerator and observed. Error Code Er FF was eliminated on the display panel. 2 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes