Wondering if the microwave relay board WB27X10859 would be the cause a no cook condition and cause the 20 amp ceramic fuse to blow? When I put a 120 volt light across the fuse holder, the light comes on dimly when the door is opened. (37 volts AC found testing both ends of fuse holder. When the cook cycle is started, the light flashes very bright. The display shows the message "Power Failure" and shuts off the cycle. I have disconnected and tested all loads and have not found any shorted items,(light, fan, door switches, elements, hi voltage system). This microwave has a main control board, a relay board and a power board. Any ideas?