Cannot Sew Pattern Well - Baby Lock BLMY Service Manual

Failure Investigation for Electronic Parts Cannot sew pattern well
Normal pattern is not generated
With the power OFF, can you lightly
move the needle bar left and right by
hand?
Is the resistance between pins 1 & 2
and pins 3 & 4 on the Z pulse motor
and F pulse motor connectors 4 – 6 Ω ?
When the upper shaft pulley is slowly
turned by hand, does the voltage
between pins 4 & 1 and pins 5 & 1 on the
main NF3D PCB assy. vary 0 – 5 V DC?
Replace main NF3D PCB assy.
Y
Y
Y
N
Adjust the attachment of the
needle-presser module
N
Replace pulse motor
N
Replace NP F2 PCB assy.
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