Brother XR9000 Service Manual page 145

Repair Manual
Problem Primary factors and causes
1 Stitch skipping Needle tip damaged while
Thread abrasion sewing
Thread breakage Needle catches and bends
Seam unevenness before or after sewing
Needle breaks
2 Power supply LCD unit (single light guide
enter, but LCD assy.) connector disconnected
display nothing
Bad LCD unit (single light guide
assy.)
Inlet assy. and power PCB assy.
connector disconnected
Bad power supply cord
Bad power PCB assy.
Power PCB assy. and main PCB
assy. connector disconnected
Bad main PCB assy.
Main PCB assy. and operation
PCB assy. connector
disconnected
Bad operation PCB assy.
Sewing machine Bad LED lamp assy.
lamp (LED lamp)
does not light
LED lamp assy. and operation
(machine operation
PCB assy. connector
normal)
disconnected
Bad operation PCB assy.
Bad main PCB assy.
3 Even when the Bad Presser switch assy.
presser foot is attachment position
raised with a
straight line
Bad Presser switch assy.
pattern, the sewing
machine will not
work (SS LAMP
does not change
green)
4 Straight left base Bad left base line needle drop
line stitch adjustment
unevenness (pitch) Loose zigzag adjusting nut
6 - 2
Repair method
Needle replacement
Plug connector in (3-16)
Replace LCD unit (single light
guide assy.) (2-10) (3-15)
Plug connector in (3-12)
Replace power supply cord
Replace power PCB assy.
(2-14) (3-12)
Plug connector in (3-13)
Replace main PCB assy.
(2-13) (3-13)
Plug connector in (3-13)
Replace operation PCB assy.
(2-10) (3-16)
Replace LED lamp assy.
(2-9) (3-16)
Plug connector in (3-16)
Replace operation PCB assy.
(2-10) (3-16)
Replace main PCB assy.
(2-13) (3-13)
Adjust Presser switch assy.
attachment position
(2-38) (3-38)
Replace Presser switch assy.
(2-38) (3-38)
Adjust left base line needle drop
(4-6)
Items for Inspection method
Inspection and standards
Tip damage to Touch the needle tip
needle with your finger, be
sure that it is not
damaged.
Needle curvature Remove the needle,
place on level block
(horizontal block) and
be sure there is no
curvature.
Sewing machine When power is
runs when switched ON, conform
switched on that there is a beep,
that the LCD screen
light.
Presser switch When the lift lever is
function lifted down and press
the SS-button, check
that machine operation
normal.
Left base line Refer to Left base line
needle drop needle drop.
(4-6)