Stitch Length And Zigzag Width Cannot Be Done By Manual Adjustment - Brother NV4000D Service Manual

Failure Investigation for Electronic Parts
Stitch length and zigzag width
cannot be done by manual
adjustment.
Does the LCD panel display change
when the manual key for stitch length
and the manual key for zigzag width
are turned ON and OFF normally?
Is the resistance between the pins
at the ends of each pulse motor
lead wire 1 Ω or less?
Z pulse motor lead wire
Between pins 1 & 1, 2 & 2, 3 & 4, and 4 & 3
F pulse motor lead wire
Between pins 1 & 1, 2 & 2, 3 & 3, and 4 & 4
Is the resistance between pins 1 & 2
and 3 & 4 on the Z and F pulse
motor connectors normal?
Stitch length and zigzag width cannot be
done by manual adjustment
Y
Y
Y
Replace main PCB assy.
N
Adjust or replace the touch
panel.
N
Replace the pulse motor lead
wire.
N
Replace pulse motor
Z pulse motor Z: 5 -7 Ω
F pulse motor: 4.5 - 6.5 Ω
5 - 13