FGMV173KBB Frigidaire Microwave

Hi Tom, Thank you for your question. If your microwave will not turn on, the part that fixes the issue most of the time are the door switches. The door switches, often referred to as primary or secondary interlock switches, provide power to the various components in the microwave when the door is closed, and interrupt power when the door is open. Sometimes it is possible that when a door switch fails, the display and controls may appear normal, but the oven won’t operate. The interlock switches are located inside the cabinet and are activated by hooks or latches on the door. Unplug the unit and remove the cabinet. The interlock switches will have wires attached to the terminals that are marked common (C) and normally open (NO). You can check the switches for continuity using a multimeter. With the actuator button depressed, you should see continuity between these terminals. If there is no continuity the switch will need to be replaced. You should also verify that the door hooks properly engage the switch actuator when the door is closed and adjust or replace it if necessary. If the door switches are fine, you will also need to check the thermal fuse. Microwave ovens use one or more thermal cut-outs, sometimes called thermal fuses, to protect the oven from overheating. They are located inside of the cabinet, often near the oven cavity or the magnetron. If the thermal cut-out fails, power is interrupted to the controls or to the control outputs. Unplug the unit and remove the cabinet. Locate the thermal fuse or cut-out and remove the wires from the terminals. Check it for continuity with a multimeter and replace the part if no continuity is shown. Verify that the cooling fan is functional and that the air flow is not restricted. We hope this helps! Good luck with the repair!