Patrick B Castle Rock , CO February 27, 2023 Appliance: General Electric Microwave CEB1590SS2SS Ge Microwave Ceb1590ss2ss: Multiple problems f4 fault and sometimes would turn off. How to replace Thermostat. Multiple fix - had an issue with the TCO and (Smart Board) Circuit Board (EBR78569501). GE Microwave working good as ever after changing those two parts. Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes