![background image](http://html1.mh-extra.com/html/baby-lock/pro-bl8800/pro-bl8800_service-manual_3396398019.webp)
- 18 -
TROUBLE
SHOOTING
OF
ELECTRICAL
P
A
R
T
S
Needle
does
not
stop
at
up
position
Check
the
Stop
sensor
by
Self
diagnostic
program
Exchange
the
STS
sensor
board
Exchange
the
CPU
circuit
board
Machine
stops
after
a
few
stitches
Check
the
T
iming
sensor
by
Self
diagnostic
program
Exchange
the
ST
sensor
board
Exchange
the
CPU
circuit
board
W
arning
is
appeared
Check
the
Feed
sensor
by
Self
diagnostic
program
Exchange
the
Feed
Sensor
board
Exchange
the
Feed
pulse
motor
W
arning
is
appeared
Check
the
Zigzag
sensor
by
Self
diagnostic
program
Exchange
the
Zigzag
sensor
board
Exchange
the
Zigazg
pulse
motor
Machine
will
star
t
although
the
presser
foot
is
lifted
Check
the
Presser
foot
switch
by
Self
diagnostic
program
Exchange
the
Presser
foot
switch
Exchange
the
CPU
circuit
board
Bobbin
wind
icon
is
appeared
although
the
Bobbin
winder
spindle
is
pushed
to
the
left.
Check
the
Bobbin
winder
switch
by
Self
diagnostic
program
Exchange
the
Bobbin
winder
switch
Exchange
the
CPU
circuit
board
At
buttonhole
sewing,
machine
will
not
star
t.
Check
the
Buttonhole
lever
switch
by
Self
diognostic
program
Exchange
the
Buttonhole
lever
switch
Exchange
the
CPU
circuit
board
Machine
runs
high
speed
Check
the
T
iming
sensor
by
Self
diagnostic
program
Exchange
the
Speed
sensor
board
Exchange
the
CPU
circuit
board
Check
the
Fuse
on
the
CPU
circuit
board
Exchange
the
fuse
Check
the
Fuse
on
the
CPU
circuit
board
Exchange
the
fuse
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
OK
NG
NG
NG
OK
OK