Motor Locks – Causes and Solutions
An increased resistance that makes it either hard or impossible for the main motor to turn the
degree wheel or pulley causing a motor lock error. Listed below are some causes of the
problem. Listed in the order that they occur most.
Lack of Lubrication
Oil the machine as specified under initial unpacking procedure. Make sure and oil the
Thread tangled in rotary hook
Open bobbin case cover and look for thread tangled in the rotary hook around it or
behind it and remove thread. Rotate pulley back to stop position after finished. This
can be caused by bird's nest, which is created by various things. Such as
Incorrect threading of machine
Incorrect needle size or type of needle for application
Needle being installed backwards
Incorrect backing for the application.
Loose upper thread tension
Inner rotary hook adjuster set incorrectly
Foreign object stuck in the rotary hook
To check if something is causing binding in the rotary hook see if you can
move the bobbin basket clockwise and counter-clockwise. The bobbin
basket is part of the rotary hook. This is part that the bobbin case fits into.
To check the play put two fingers on the bobbin case latch and rotate your
fingers in both directions. You should have a little play in both directions. If
not then there is something lodged in the raceway of the rotary hook. Clear
obstruction or replace rotary hook. This can be caused by
Broken pieces of needle lodged somewhere in hook
Thread badly entangled in rotary hook.
For Technical Assistance Please Call Toll Free 1-877-4BROTHER
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Check for broken bits of
needles in this area.