Bernina Artista 640 User Manual page 150

150 Embroidery Support
Prevention and Remedy of Failures
Note the following advice to recognize the causes of most of the
operation failures in the embroidery computer that might occur.
Check First Whether:
• upper and lower threads are threaded
correctly
• the needle is inserted correctly - flat part of
the shank to the back
• the needle is the correct size (see
Needle/Thread Chart on pages 15-17)
• the embroidery computer is clean - remove
any thread lint
• the hook race is clean
• bits of thread are trapped between the
tension disks and under the bobbin case
spring
Removing Trapped Thread
If the lower thread breaks and the thread is
trapped in the area of the take-up lever,
proceed as follows:
• power switch to «0» (off)
• remove the screw on the head frame with
the angular Torx key
• pull head frame to the left
• remove remnants of thread
• attach head frame and tighten screw
Upper Thread Breaks
Possible Faults:
• upper thread tension is too tight
• use of low quality needle. It is best to buy
needles in a BERNINA store
• needle has been inserted incorrectly. The
flat part of the shank must be to the back
• needle is blunt or bent
• use of poor quality thread, thread with
knots, thread too old or dried out
Possible Solutions:
• attach foam pad
• use appropriate spool disc
• use net for even unwinding of thread (pull
over upper thread spool)
• stitch plate hole or hook tip is damaged:
take the embroidery computer to an
authorized BERNINA dealer
• reduce embroidery speed
Lower Thread Breaks
• lower thread tension is too tight
• lower thread is trapped in the bobbin case:
• Replace bobbin
• needle is blunt or bent
• the stitch plate hole has been damaged by
the needle:
• It must be polished by a BERNINA
Technician
Skipped Stitches
• incorrect needle used:
• Use only 130/705H needle system
• needle is bent or blunt or not correctly
inserted:
• Push all the way to the top when
inserting
• low quality, badly polished needle used
Needle Breaks
• needle clamp screw is too loose
• defective stitch plate
Unsatisfactory Stitch Formation
• remnants of thread between tension discs:
• pull folded thin fabric (use the fold, not
an outer edge) back and forth between
the tension disks to clean the left and
right side of the thread tension
• remove any remnants of thread from under
the bobbin case spring
• adjust thread tension
• used wrong or no stabilizer at all
• incorrectly threaded:
• check upper and lower thread
• when embroidering, thread the pigtail
tension with the lower thread
• use appropriate spool disc
• clean and oil hook (use original oiler only.
See Cleaning and Lubricating on page 103)
Embroidery Computer Fails to Run or
Runs Slowly
• plug not fully inserted
• power switch in «0» (off) position
• embroidery computer has been standing in
a cold room
Defective Sewing Light
• take the embroidery computer to an
authorized BERNINA dealer
Upper Thread Indicator Sensor
• not activated in the Setup Program
Lower Thread Control
• bobbin cover is not closed
• not activated in set-up program
• remove any thread lint and remnants from
Calibration of the Display
To open the calibration screen directly,
proceed as follows::
• press both needle position buttons on the
body simultaneously and keep them
pressed
• turn on the sewing and embroidery
computer
• as soon as the calibration screen is opened,
release the two buttons
• Calibration of the Display see page 96
Service Data
Service data of the actual condition of your
sewing and embroidery computer can be
saved on a USB stick and sent to your
authorized BERNINA dealer:
• insert the USB stick into your sewing and
embroidery computer
• press the «Setup» button and select the
symbol «i» (information)
• use the «To Next Page» symbol to change
to the previous screen
• touch «LOG»
• data is saved on the USB stick
• remove the USB stick
the bobbin case
Update error
If the update process is at a still stand (hour
glass remains) proceed as follows:
1. Remove the USB stick and turn off the
Sewing/Embroidery computer
2. Turn on the Sewing/Embroidery
computer and proceed with the update
as indicated by a message on the display