Unicorn LS2-H530, Руководство по эксплуатации

Страница: 33 / 34

- 23 -
TROUBLESHOOTING GUIDE
Problem Cause Check Solution Page
Needle thread
escapes at
start of
sewing.
Tension disc
does not open
sufficiently.
Tension disc
opening
Adjust tension
release.
Excessive pretension ― Adjust pretension. 6
Needle too heavy for
thread
―
Use smaller size
needle.
Up needle stop
position too high,
thread removed
by thread take-up.
Thread take-up
height at up needle
stop position
Delay up needle
stop position
timing.
13
Thread cutter
mechanism
does
not function.
Thread cutter
solenoid dose not
function.
Check with tester
Replace thread
cutter
solenoid.
Thread cutter signal
not transmitted.
―
Check circuits; refe
to motor adjustment
manual
Thread wiper
does not
function.
Needle thread
remainder too long.
― Adjust pretension 6
Timing too early;
wipes thread before
tension disc closes.
― Adjust timing.
Excessive material,
presser foot
resistance
―
Replace with
presser foot having
back channel.
Thread wiper
operation too short
―
Adjust operation
time.
Material end is
not cut during
sewing.
Gap between upper
and lower knife
―
Reposition upper
knife
11
improper engagement
of upper and lower
knives
―
Adjust overlap of
two knives
11
Upper knife is dull ―
Replace upper
knife
Material is not
cut properly at
corners.
Upper knife
positioned too far
forward
―
Reposition upper
knife
11
upper knife
posotioned
too far to rear
―
Reposition upper
knife
11