Unicorn LS2-H530, Operation Manual

Page: 27 / 34

- 17 -
Problem Cause Check Solution Page
Needle
breakage
Improper needle
installation Needle facing,
height
Reinstall needle. 4
Bent needle
Blunt needle tip
jammed eye Needle Replace needle 4
Improper feed timing _ Adjust feed timing. 8
Improper needle to
rotary hook timing
Needle bar stroke
Adjust needle to
rotary hook timing.
8
Needle bar height
Adjust needle to
rotary hook timing.
8
Needle to rotary
hook gap Adjust needle to
rotary hook timing.
8
Thread wiper too high
Thread wiper
position
Adjust thread wiper
position with screw.
Thread
breakage
Improper threading Threading Rethread. 4
Bent needle
Blunt needle tip
jammed eye Needle Replace needle 4
Improper needle
installation
Needle facing,
height
Reinstall needle. 4
Excessive needle
thread tension Needle thread
tension Adjust needle
thread tension.
6
Excessive bobbin
thread tension
Bobbin thread
tension
Adjust bobbin
thread tension.
6
Loose needle thread
Thread take-up
spring operation
Adjust thread
take-up spring.
6
Insufficient rotary hook
lubrication
Oil supply Adjust oil supply. 2
TROUBLESHOOTING GUIDE