Bernina COLLEGE 455 User Manual page 109

Errors and faults
Fault
Upper thread breaks
Lower thread breaks
Needle breaks
Stitch width not adjustable
108
Cause
Incorrect needle/thread
combination.
The upper thread is too tight.
Incorrectly threaded.
Poor quality thread.
The stitch plate or the hook tip is
damaged.
The thread is caught in the area
of the thread take-up lever.
1
The bobbin case is damaged.
The stitch hole in the stitch plate
is damaged.
Needle blunt or bent.
The needle is incorrectly inserted.
The fabric has been pulled.
Thick fabric has been pushed.
Knotted thread.
The selected needle and stitch
plate cannot be used in
combination.
Repair
> Match the needle with the thread size.
> Reduce the upper thread tension.
> Rethread.
> Use quality thread.
> Contact the nearest specialized BERNINA dealer to have
the damages repaired.
> Replace the stitch plate.
> Slide the headframe (1) to the left, then remove it.
> Remove the thread remnants.
> Insert the 4 knobs of the headframe into the provided
notches and slide the headframe to the right.
> Replace the bobbin case.
> Contact the nearest specialized BERNINA dealer to have
the damages repaired.
> Replace the stitch plate.
> Replace the needle.
> Insert the needle with the flat side to the back as far up
as it will go into the needle holder and tighten the
screw.
> Feed the fabric evenly.
> Use the appropriate presser foot, e.g. Jeans foot No. 8
for thick material.
> Use the height compensating tool when sewing over a
thick seam.
> Use quality thread.
> Replace the needle.
> Replace the stitch plate.