SunStar KM-250 Series, Руководство пользователя

Страница: 29 / 31

29
4
Cause of troubles and troubleshooting
1) Sewing machine troubleshooting
No Symptom Checkpoints Root cause Corrective action
1
2
Needle breaks
Direction and height of needle
Needle
Ascending level of needle bar
Height of needle
Gap between needle and hook
Threading method
Needle
Direction and height of needle
Upper thread tension
Lower thread tension
Working capacity of take-up lever spring
Direction and height of needle
Needle
Threading
Ascending level of needle bar
Height of needle bar
Gap between needle and hook
Needle is inserted into wrong position.
Needle is bent.
Bad timing of feed dog.
Bad timing of needle and hook.
Bad timing of needle and hook.
Bad timing of needle and hook.
Wrong threading.
Bent needle or broken needle tip.
Needle inserted in the wrong position.
Too tight upper thread tension.
Too loose lower thread tension.
Loose upper thread.
Needle inserted in the wrong position.
Bent needle or broken needle tip.
Thread passing at wrong position.
Wrong timing of needle and hook.
Wrong timing of needle and hook.
Wrong timing of needle and hook.
Remaining length of upper thread is short .
Due to bobbin racing during
trimming, lower thread dropping
from bobbin case becomes too
short to go up.
Racing-proof spring
of bobbin case
Unable to lift lower thread due to
weak take-up lever spring.
Take-up lever spring
Reinsert the needle correctly.
Change the needle.
Adjust the timing of feed dog.
Adjust the timing of needle and hook.
Adjust the timing of needle and hook.
Adjust the timing of needle and hook.
Thread the needle correctly.
Change the needle.
Insert the needle correctlyz.
Reduce tension of upper thread.
Reduce tension of lower thread.
Adjust take-up lever spring.
Reinsert the needle in the right direction.
Change the needle.
Change the needle.
Adjust the timing of needle and hook.
Adjust the timing of needle and hook.
Adjust the timing of needle and hook.
Adjust the thread adjusting device.
Change the racing protection
spring.
Adjust the working capacity of take-
up lever spring.
Thread breaks
3 Stitch skips
Keystone Sewing Machine Company, Inc.