10. TROUBLESHOOTING
RH-9820
226
Problem Cause
Remedy
Page
Needle is bent.
Replace with a new needle.
Needle, looper and spreader adjustment
is incorrect.
Adjust correctly.
141
146 – 151
Needle guard is covering the needle too
far.
Adjust the needle guard.
149
Broken needle
Needle is too thin.
Select a needle that is suitable for the
sewing conditions.
Instruction
manual
Upper movable knife is blunt.
Replace the upper movable knife with a
new one.
166, 167
Upper movable knife does not move to
the full stroke because air pressure is
too weak.
Adjust the air pressure.
Instruction
manual
Upper movable knife is not picking up
the upper thread.
Install the upper movable knife so that it
cuts only one side of the upper thread
loop.
167
Upper movable knife is not picking up
the upper thread because the last stitch
is being skipped.
Refer to the remedies given under
“Skipped stitches occur” in this
troubleshooting chart.
225
Upper thread is not cut.
Upper movable knife position is
incorrect.
Adjust the position of the upper movable
knife.
167
Movable knife is blunt.
Replace the movable knife with a new
one.
169, 174
Movable knife does not move to the full
stroke because air pressure is too weak.
Adjust the air pressure.
Instruction
manual
Movable knife position is incorrect.
Adjust the position of the movable knife
or the thread handler.
170, 173
175
Lower thread is not cut.
Cutting pressure for lower thread
trimming is too weak.
Adjust to an appropriate cutting
pressure.
170, 174
Lower thread is not being held.
Adjust the lower thread nipper (-01
specifications) or the lower thread
presser (-02 specifications).
171, 173
180
Upper thread length is too short after
trimming.
Adjust the sub tension.
Instruction
manual
Thread unravelling at
sewing start
Not enough upper thread is being fed
out.
Adjust the amount of upper thread being
fed out.
165
Cutting pressure is too weak.
Adjust the cutting pressure so that it is
strong enough.
160
Knife and hammer are not contacting
properly.
Grind the hammer surface.
154
Material is not being cut
cleanly.
Knife is blunt.
Replace the knife with a new one.
157
Upper thread tension is too strong or too
weak.
Adjust the upper thread tension to the
correct tension.
Instruction
manual
Lower thread tension is too strong or too
weak.
Adjust the lower thread tension to the
correct tension.
Instruction
manual
Poor thread tightening
Tension or stroke of thread take-up
spring is incorrect.
Adjust the tension and stroke of the
thread take-up spring.
Instruction
manual
Summary of Contents for RH-9820
Page 7: ...RH 9820 v Belt cover Rear 0331B 0332B 0334B 0486B 0485B 0333B ...
Page 46: ...4 MECHANICAL DESCRIPTIONS RH 9820 37 ...
Page 58: ...5 DISASSEMBLY RH 9820 49 5 10 Lubrication 1089B ...
Page 124: ...6 ASSEMBLY RH 9820 115 6 19 Covers 1064B ...
Page 210: ...8 ELECTRICAL MECHANISM 201 RH 9820 PMD P C board Power supply motor P C board 0693B 4593Q ...
Page 211: ...8 ELECTRICAL MECHANISM 202 RH 9820 Panel P C board 0694B ...
Page 217: ...8 ELECTRICAL MECHANISM 208 RH 9820 0761B ...
Page 218: ...8 ELECTRICAL MECHANISM 209 RH 9820 0762B ...
Page 236: ...SERVICE MANUAL RH 9820 I6100920B 2007 03 B 1 Printed in Japan ...