My microwave oven quit working. the humidity sensor shows it is open so I jumped out the sensor and everything works ok except that it will not heat. I put a neon bulb and a cup of water in the oven but the bulb will not stay on very long and the water temp. will only rise very little. The HV capacitor checks ok with a capacity checker (1.1 uf ) and the diode shows resistance in one direction. The Hv transformer has 120 volts ac when I push the start button. I don't know what the resistance reading should be for the transformer primary or secondary. The magnetron between f and Fa is not open nor is it shorted to ground. Could it be possible for the capacitor to be breaking down after the power is on for a short time even though is checks ok with a meter? Anyone have any sugestions?