Module failed/short: With tool unplugged rotate
the bare spindle back and forth swiftly by hand
and feel for a viscous like resistance to
turning; in that the resistance increases as
speed is increased. Its best to compare this
turning resistance against a known good unit
to help understand how it should feel. If this
higher resistance is felt then either the module
or stator has shorted causing the increased
resistance.
With tool unplugged remove handle covers
and shrink tube caps from the three motor-
module connections. Disconnect the three
motor-module connections while continually
checking the spindle turning resistance. If the
spindle resistance is significantly reduced
when the phases are disconnected the module
is shorted and must be replaced.