Microwave starts running as soon as door is closed and strats cooking

Hi @freefall57167

You may need a DMM but not to test the door interlock switches.

Looking at a schematic for the oven (see image below) the only way that the oven would turn on i.e. light on, fan on, turntable turning and cook when you close the door without pressing the start button on the control panel, is if the contacts of the power relay on the control board were permanently operated i.e. sticking or if the Start button on the control panel was stuck in the operated position (or if its contacts were short circuit).

To verify either scenario you would have to disconnect the power to the oven and then open the oven to gain access and then connect the DMM between the neutral wire on the power cord and one side of the monitor door interlock switch (usually the middle switch) and check that there's no continuity i.e. open circuit - infinite Ohms, when the door is closed.

If there is continuity then the contacts of the power relay are short circuit (when they shouldn't be).

If there is no continuity then perhaps the Start button is the problem.

Unfortunately with your model, when searching online I can't find any replacement parts at all, if there's a part that needs replacing. You may have better luck.

(click on image)

Note: I've highlighted the 3 door interlock switches and the Power relay on the control board, just for reference. Measure between the two points as shown by the red arrow