I am shocked by how many people look at me like I've grown a second head when I tell them I unplug my machines when they are not in use. I do every time. I shut them off and unplug them every time. But I also do not sew during a bad storm either. Here's why :
Granted I know the chances of it happening are slim, but I'm not willing to take that risk. Usually the motherboard is what gets damaged the most. Many models of older machines have parts like the motherboard that are nearly impossible to get replacements for. Even some newer models don't have a grand stock of replacements out there.
Can a motherboard be replaced? Yes.
Will there be other damage? More than likely.
Do I want to part with my machine? Never.
Especially with the long arm, I cannot risk losing days or even weeks to replace parts or my entire machine with a stack of customer quilts waiting for me. It's just not practical. So Mom and I both have adopted the practice (or habit more truthfully) of unplugging our machines.
It is more than just storms though, rolling brown or black outs are extremely harsh on electronics. A blown fuse, an unexpected power surge, they're all lot fun and not good for your stuff. It's just best to be safe!
So I ask again, do you unplug your machines? Or will you consider it in the future?