Failure Investigation
for Electronic Parts
The pattern is not sewn correctly.
With the power OFF, can you lightly more
the needle bar left and right by hard?
Is the resistance between pins 1 &
2 and 3 & 4 on the Z and F pulse
motor connectors 6.7-7.7Ω?
Is the Z pulse motor connector
correctly connected to the main
PCB assy. (CN10)?
Is the F pulse motor connector
correctly connected to the main
PCB assy. (CN11)?
Replace the main PCB assy.
Cannot sew pattern correctly
Y
Y
Y
Is the BW switch OFF?
Y
N
Adjust the attachment of the
needle-presser module.
N
Replace the pulse motor.
N
Connect it properly.
N
Reassemble the BW switch assy.
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