Hate to say it but it never even occured to me to unplug. I use a surge protector because was told to as my beloved Janome is computerized but I probably deal with less thunderstorms in so cal too. When I think of considerations for computerized machines I think of no magnets (how do they use that new magnetized hoop I wonder!) and quality of thread. Cheap cotton frays more and more lint is not good. As for the serger part I am clueless. I inherited a Babylock evolve and a giant cardboard box of serger thread I have yet to use. What does a dedicated quilter do with a serger?