Thread Tensioning Does Not Go Well - Baby Lock BLMY Service Manual

Failure Investigation for Electronic Parts Thread tensioning does not go well
Is the lower thread placement correct?
Is the material, thread and needle
combination correct?
Is the tension right?
Is the thread tension adjuster gap correct?
Is the inner rotary hook tension right?
5 - 14
Thread tensioning is not right
Is the thread guide path correct?
Y
Y
Y
or
Y
Y
Is the resistance between the 1 & 2
pins and 3 & 4 pins on the AT pulse
motor connectors (CN10) 4 – 6 Ω?
Y
Replace main NF3D PCB assy.
N
Set thread correctly
N
Set the lower thread correctly
N
Use the correct combination
Adjust upper thread tension
N
or
Adjust upper thread tension disk
N
Adjust inner rotary hook tension
N
Replace pulse motor