Customer Questions and Answers for Microwave Diode Cable Assembly by Ge

David, the diode WB27X35382 can certainly cause the buzzing sound and can prevent the unit from heating. However, the buzzing should not occur until the microwave is put into a cooking cycle. As it is buzzing when the door is closed, you may want to test the main control (with the power disconnected from the unit) at relay 2 and relay 5 (red and yellow wires to the yellow and white wires) for continuity. If there is continuity, then the relays are stuck closed and the main control WB27X10931 would need to be replaced. Unfortunately, the manufacturer has discontinued the main control and it is no longer available.