My microwave continues to run, (turntable and exhaust), when the door is opened.

Yes. Faulty door interlock switches.
Replace the door switches with the correct ones.

It is a cooling fan used for cooling of magnatron as the temperature of magnatron rises when microwave mode is used, cooling saves this component from any defect.

The door switch is adjustable. one or more need adjusting to solve the problem

I'd look for a defective relay or shorted triac on the control panel circuit board. Either could cause this problem.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/david_29ad5d1dd86564b0

follow this test and fix it. God bless you

1. Exhaust fan motor If your exhaust fan motor is not running, there are a couple of things that you can check involving the motor to locate the problem. After removing the fan motor, you can manually attempt to turn the fan blades with your hand. If the fan motor is working properly, the blades should spin effortlessly. If this does not occur and the blades are taught, the motor will need to be replaced. Secondly, the fan motor itself can burn out due to time and usage. Using an ohm meter, the exhaust fan motor should read open for continuity. If it does not, then the fan motor has expired and will need to be replaced.
   
2. Thermostat Another part that could cause the microwave exhaust fan to not work is a faulty thermostat. A thermostat gauges the air temperature, which activates the exhaust fan when required. If this part becomes flawed, the exhaust fan will not energize and the thermostat will need to be replaced.
   
3. Main control board If your exhaust fan is still not working and the microwave fan motor, wiring, and thermostat are operating accurately, the root cause could be with the main control board. Replace the main control board.
   

measure this test and use the multimeter for fix it. GOD BLESS YOU

1. Exhaust fan motorIf your exhaust fan motor is not running, there are a couple of things that you can check involving the motor to locate the problem. After removing the fan motor, you can manually attempt to turn the fan blades with your hand. If the fan motor is working properly, the blades should spin effortlessly. If this does not occur and the blades are taught, the motor will need to be replaced. Secondly, the fan motor itself can burn out due to time and usage. Using an ohm meter, the exhaust fan motor should read open for continuity. If it does not, then the fan motor has expired and will need to be replaced.
   
2. ThermostatAnother part that could cause the microwave exhaust fan to not work is a faulty thermostat. A thermostat gauges the air temperature, which activates the exhaust fan when required. If this part becomes flawed, the exhaust fan will not energize and the thermostat will need to be replaced.
   
3. Main control boardIf your exhaust fan is still not working and the microwave fan motor, wiring, and thermostat are operating accurately, the root cause could be with the main control board. Replace the main control board.
   

The high pitch sound to me may be coming from the speaker on the main circuit board. Try to unplug for a few minutes, reset clock time and then try again. If same issue, may need new PC board. When you say Microwave continues to run are you meaning the Turntable is turning and the fan running?? Or is it just timing down. Almost never does it actually keep heating. On GE units I mostly find bad door switches will cause a back feed and make the tray turn and the cooling fan for the mag to run. To see if that is the problem You have to look at the door switches behind the front panel on the left side and see if any of them have any browned connections on the terminals where they push ontl the back of the switch. That will cause the fan and turntable toi run, but wouldnt cause a high pitch squeal. These companies use switches wtih small 3/16 terminals that dont give a good enough grab on the switch, they get loose and hot and make the switch go bad. I replace that switch with a switch with 1/4 inch terminals and runa short section of Hi temp wite to it and it wont go bad again. Just cheaply made!! Also I guess the squeal could come from the turntable motor area. So By fixing the switch problem it could fix your squeal. With nothing else running you may be able to hear motor and coupling noise you couldnt hear before.

With the model number, we can offer more specific advice or an estimate.

But since FixYa does not notify us of follow-ups, you will need to post a new help request.

If the cooling fan, light and turntable run continuously when the door is open, but not when it is closed, your secondary interlock (bottom door switch) is shorted (always on).

Even if it's shorted, the actuator button (usually red) will still move up and down when you open and close the door.

It will need a new door switch.

See the service manual here. See our file on door switches here.

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