Bernette b77 - Page 96

Errors and Faults
96
2022-08 EN 5020077.40A.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
is 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.
The eco Mode is active. > Tap «eco Mode».
Stitch Width Not Adjustable
The selected needle and stitch
plate cannot be used in
combination.
> Replace the needle.
> Replace the stitch plate.