CONCERN: Customer reports microwave is not working properly. CAUSE: Tested Microwave door switches for continuity, found microwave interlock door switches have electrical short and failed. CORRECTION: Replace microwave interlock door switches and tested. Operation now normal. CONCERN: Customer reports microwave is not working. DIAGNOSTIC AND CAUSE: Inspected power supply at the wall for 120V, voltage at supply line normal at time of inspection. Inspected control board for visible signs of shorts, no signs of shorts a the control board. Inspected microwave 20 amp safety fuse for shorts. Microwave fuse shorted. CORRECTION: Replaced microwave fuse and tested, operation now normal.