Bernette b77 - 11.4 Cleaning the Hook

Appendix
90
2020-02 EN 5020077.20A.04
Fault Cause Repair
Upper thread breaks
Incorrect needle/thread
combination.
> Match the needle with the thread size.
Upper thread is too tight. > Reduce the upper thread tension.
Incorrectly threaded. > Rethread.
Poor quality thread. > Use quality thread.
The stitch plate or the hook tip is
damaged.
> Contact a specialized bernette dealer to have the
damages repaired.
> Replace the stitch plate.
Lower thread breaks
The bobbin is not inserted
correctly.
> Remove and reinsert the bobbin and pull on the thread.
– The thread should run easily.
Bobbin is wound incorrectly. > Check bobbin and thread correctly.
The stitch hole in the stitch plate
damaged.
> Contact a specialized bernette dealer to have the
damages repaired.
> Replace the stitch plate.
Needle blunt or bent. > Replace the needle.
Needle breaks
The needle is incorrectly inserted. > 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.
The fabric has been pulled. > Feed the fabric evenly.
Thick fabric has been pushed. > 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.
Knotted thread. > Use quality thread.
Display is inactive
Incorrect calibrating data. > Switch the machine off.
> Switch the machine on and simultaneously press and
hold down the buttons «
Needle left/right».
> Recalibrate the display.
eco mode activated. > Touch the icon «eco».
Stitch width not adjustable
The selected needle and stitch
plate cannot be used in
combination.
> Replace the needle.
> Replace the stitch plate.