I have a GE Spacemaker XL 1800 microwave above my stove. Today I noticed that the light was coming on by itself for a few seconds and then shutting off even when the door was closed. This happened about 3 times during a 10 minute period. I then kept the door open(light off) and went out for a few hours. Came back and the light was on(door still open).I shut the door and the microwave started up, pushed the STOP button but it would not turn off, opened the door and then it shut off(light still on). I unplugged the unit from the outlet for 10 seconds and then replugged it in, closed the door and it came on without touching any buttons. Panel displayed PUSH CLOCK but buttons did not work. Tried the SURFACE FAN button and I got a buzzing sound with the fan running. By the way, when I plugged in the cord the display showed a garbled LED characters, then it went to regular characters. Does anyone know what's going on with this unit? Thank you.

Hello,

You may want to start the troubleshooting from testing the primary interlock switch (the very bottom door switch) for continuity. Unplug the microwave. Open the control panel and remove the wires from the switch. The normal readings between the COM & NO terminals should be: with the door open - ∞ Ohms; with the door closed - 0 Ohms.

If any of the readings is incorrect or any wires or switch terminals are burned, replace the switch.

- The primary interlock switch Part number: WB24X829

Unplug the microwave. Remove the screws on top of the microwave secured the top grille and remove the grille. Remove the screw on top of the control panel and pull the upper part of the control panel toward yourself.

Gene.