Originally Posted by sewtruterry
If your machine needle vibrates when you turn on the machine it means that you have a computerized machine and it is calibrating the needle.
It is not falling off the needle bar when it calibrates, but when I turn the needle wheel.
The needle broke because it struck the sole-plate. The needle had been falling in front of the sole plate, rather than in the hole designed to accept the needle. I didn't realize it was misaligned until it broke, then I noticed that while I managed to get the walking foot to work for a bit (couldn't get it to do it again), it still was not on properly.