Sharp Model R1810 Carousel II microwave starts and cooks(heats) but
shutsdown after about 40 seconds. Electronic control board display
stays lit, countdown stops and displays remaining time--magnetron
cooling fan works during the first 40 seconds but then shutsoff--just
before shutdown, fan speed increases(doubling or tripling in speed)
These items seemed to check out good with VOM--
power fuse
interlock switches (2)
monitor switch
capacitor
diode
thermal cutout switch(only found one)
fan motor
power tranformer

Additional trouble shooting note--a power surge protector I had plugged
the microwave into was discovered fried--suspect a near by lightning
strike?

Read an informative article by Sam Goldwasser-- "NOTES ON MICROWAVE
OVEN FAILURE DIAGNOSIS AND REPAIR v1.01" but need more help. Thanks