33Trouble shooting
Trouble shooting
Upper thread breaks
•
The upper thread tension
is too tight.
•
The needles are of a poor
quality. Ideally needles should
be purchased from your
BERNINA dealer.
•
The needle is bent or blunt.
•
Poor quality, knotted or dried
out thread has been used.
•
Use the correct spool disc.
•
Stitch plate or hook tip
damaged. Take your sewing
computer to your BERNINA
dealer.
Lower thread breaks
•
The lower thread tension is
too tight.
•
The bobbin is jamming in
the bobbin case. Remove and
replace the bobbin.
•
The hole in the stitch plate
has been damaged by the
needle. This must be
repolished by an expert.
•
The needle is blunt or bent.
Skipped stitches
•
Wrong needles used. Use only
130/705H system.
•
The needle is blunt, bent or
incorrectly inserted.
•
Push right to the top when
inserting.
•
Needle inserted all the way
to the top.
•
The needle point does not
suit the fabric being sewn.
If necessary use a ball point
for knitted fabrics and
cutting point for hard leather.
Needle breaks
•
Needle clamp screw loose.
•
Fabric taken out in front
instead of behind presser foot.
•
When sewing over thick area,
the fabric was pushed with
the needle still in the fabric.
•
Poor quality thread, unevenly
wound or knotted.
•
See pages 29 and 30 for
information about needles.
In most cases you will be able to identify and remedy faults
by checking the following.
Check whether:
•
the upper and lower threads are threaded correctly
•
the needle is inserted correctly
•
the needle size is correct – check the needle/thread table p. 29
•
the sewing computer is clean – brush out any thread fluff
•
the hook race is clean
•
any threads are trapped between the tension discs or under the
bobbin case spring
•
the bobbin runs smoothly in the case or if remnants or lint need
removing
Faulty stitching
•
Remnants of thread between
the tension discs.
•
Remnants of thread under
the bobbin case spring.
•
Lower thread still threaded in
the bobbin case finger.
•
Sewing computer threaded
with foot down.
•
Incorrect threading. Check
upper and lower threads.
•
Use the correct spool disc.
Sewing computer fails to run
or runs slowly
•
Plug not properly inserted.
•
Power switch in off position.
•
Sewing computer has been
standing in a cold room.
•
Bobbin winder still switched
on.
