Troubleshooting - Bernina a170 Manual

Trouble shooting
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 as far up as possible with the flat
side to the back
· the needle size is correct – check the needle/thread
table
· the machine 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
Upper thread breaks
· the upper thread tension is too tight.
· the needle is not designed to be used with the selected
thread. Check the chart on page 65–66 and the
Creative Consultant.
· the needle has been inserted incorrectly. The flat side
of the shank must be to the back.
· 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 machine 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 polished by a Bernina Certified
Technician.
· 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.
· 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 forwards instead of behind the 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.
030787.52.04_Nähen_04-01_a165 a170 a180_EN
Faulty stitching
· remnants of thread between the tension discs.
· remnants of thread under the bobbin case spring.
· the thread is still threaded in the finger of the bobbin
case.
· incorrect threading. Check upper and lower threads.
· use the correct spool disc.
Machine fails to run or runs slowly
· plug not fully inserted.
· power switch in off (0) position.
· machine has been standing in a cold room.
· bobbin winder still switched on.
Machine sews in reverse
reverse sewing function is still activated.
Defective sewing light
Please note that it is forbidden to change the new CFL-
sewing light by a unauthorized person. For Models with
this new CFL-sewing light, the light can ONLY be repla-
ced by an authorized Bernina Dealer.

Troubleshooting

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