We have all gone through these obstinate occurances with our machines: bobbin wound wrong, presser foot down so thread is not in disks, lint behind the bobbin case, and yes, not turned on. The three items that have eliminated a lot of frustration for me are: put in a new needle, check to see if the thread is in the last loop just above the needle and always pull thread out a few inches before sewing, even on the computer machines. As my son, the engineer, says, "Mom, remember your working on an inanimate object. Think of it as a puzzle." Let us know how you're doing.
Mary Ellen
FL