Me too. My brother which was bought last January jammed up on me several weeks ago. I took it apart and worked and worked cleaning the bobbin case, changing needles, rethreading etc. Nothing worked.
Someone here on the board asked if I had unplugged it--well, no. I did just that, but no luck . I put it under my sewing table, pulled out my old white and kept going. I pulled it out last week to take to the repair shop and thought I'd try it one more time. Turned it on and voila,
It worked and I've been using it ever since.
Roxanne