Bight stepper motor no
operation
Check if Cable (J3)
has loosened
Replace Photo-sensor switch (J7) or Motor or PC Board
Yes
Be sure plug-in
No
Feed stepper motor no
operation
Check if Cable (J2)
has loosened
Replace Photo-sensor switch (J6) or Motor or PC Board
Yes
Be sure plug-in
No
Function and stitch selection
key no operation
Check if Bus (J5) has loosened
Replace PC Board
Be sure plug-in
Yes
No
Replace Photo-sensor
switch or PC Board
Yes
Please refer to Page 29 for
BH adjustment
No
BH no operation
Check if an indentation at
the top of BH arm is
positioned in the center of
Photo-sensor switch
Yes
No
Check if Cable (J10)
has loosened
Be sure plug-in
Alarm no operation
Replace PC Board
Sewing machine
no operation
Check if Fuse is blown
Yes
No
Yes
No
Check if Transformer
is damaged
Replace Fuse
Replace Motor or PC Board
Replace Transformer
7. Trouble shooting of electrical parts
33
Model 9300A