More than likely, the computer is seeing an electrical fault and spitting up that code.If I had to guess, the transformer or transducer is shot.
FWIW, I was chatting with the sales help at a retail outlet while the Polish Princess was picking out her new microwave. I mentioned to him that our Amana Radar-range had expired almost 15 years exactly to it's build date. He replied that the new machines were built with lower quality control and parts reliability but that they also cost 1/3 of what we paid for the Amana. He also noted that I could expect about 1/3 the lifetime. He was probably right but the Sharp we purchased is over 10 yrs. old and still humming.