Bob Engelhardt wrote:
I have a Milwaukee 12v cordless jig saw. It was working fine then
stopped, dead. Then started again, with no symptoms. It did this
back & forth a few times, then stayed dead. It never stopped while
being used - it just wouldn't start at all.

One bad winding on the motor, a bad spot on the commutator, really
worn brushes? (Assuming it's not brushless.)

To check: Get it to the dead state again. With your fingers off of
the trigger, use a stick of wood or something that's not your fingers to
turn the blade a few degrees. Then try the trigger again. If you can
reliably make it start that way, look at the brushes and commutator.

Matt Roberds