Brother NX600 Service Manual page 210

Repair Manual
Problem Primary factors and causes
16 • Seam Seam unevenness.
unevenness
• Bad presser position
• Cloth presser is high and
• Inner rotary hook scratches Replace inner rotary hook
• Outer rotary hook scratches Replace outer rotary
• Scratches around needle
• Scratches around presser
• Burrs and scratches in
• Slippage from lower thread
• Tension loosened by thread
• Bad thread guide plate
• Needle plate scratches
Bad presser dial position
• Stops during Stops during sewing.
sewing
• No gap for bobbin winder
• No gap for BH lever switch
• No play in S/S button,
17 BH lever LED BH lever LED lights, and it
lights. cannot start.
• Because of BH lever switch
• BH lever switch lead
When started, BH lever LED
lights.
• BH connector disconnected Plug connector in
• BH lever switch bent
• BH lever switch guide
6 - 8
does not hold material
completely
plate needle hole
foot needle hole
thread guide path
tension spring
scraps and dirt adhering to
the thread guide plate
shape (bent)
switch
reverse button or vertical
stop button
deformation, the switch is
usually on
insulation is torn, and it is
shorting with metal parts
broken / switch displaced
Repair method
Readjustment of presser bar
height (4-13)
Readjustment of presser bar
height (4-13)
hook(3-70)
Replace needle plate A(3-73)
Replace presser
Replace parts with burrs and
scratches
Reset lower thread
Remove thread and dust on
stuck to thread guide plate
Replace thread guide plate(3-
20)
Replace needle plate A(3-73)
Replace needle-presser module
(3-4)
Readjust BW switch assy.
position (3-14)
Adjust BH lever switch position
(4-19)
Reassemble SS-VR F PCB
assy.
(3-35)
Replace BH switch assy.(3-59)
Replace BH switch assy.(3-59)
Replace BH switch assy.(3-59)
Replace BH switch assy.(3-59)
Items for Inspection method
Inspection and standards
Check that stitches are
not uneven during
actual sewing.
Operation of Check that presser bar
presser bar pressure is effective
when presser dial is set
to 1 and lower presser
foot lifter slowly. (Check
that there's some
resistance when lower
feed dog and insert a
paper between needle
plate and presser foot,
and then pull the paper
out of them.)
Check that it does not
stop during actual
sewing.
BH lever switch With the BH pattern
position function selected and the BH
lever switch down, and
when straight line is
selected and the BH
lever switch is up,
confirm that the S/S
button shines green.
(4-13)