Ill
Explanation
of
connectors
If
the
machine
has
been disassembled
or
adjusted during repairwork, most
of
the
machine
troubles
are
due
to
connector problems including improperconnection
or
weakcontact.
It
is,
therefore,
necessary
to
check
each connector numberand pin contact
for
correct connection prior
to
proceeding
to
thetroubleshooting
procedures.
The
table
below
lists
the
connectornumbersand symptoms resulting
from
wrong
connections. For detailed
connectorand harnessarrangement, refer
to
•coNTROL
CIRCUIT
BLOCK
DIAGRAM•.
Connector No. and location
Main
PCB
I P8 I
I P3 I
PMDPCB
I .MainPCB I
I
P6
I I
PS
I
m [5[5
ElBg
I J11 I
Solenoid
Air
valve
~In~
~~
PS
Y
nlsve.
pu
a
motor
I
Motor
ll
Main
PCB
I
-[ L
·I
P13
LJ
;.
I:
:I
I:
1:
:~M+r:
:1
I I I 1 I
I
PMD
I
I I
Main
PCB
I P14 I
~
I P2 I
r.
Synchronizer
l
Drivesignalsand source
Control
power
source
Solenoiddrivepower
source
Pulse
motor
drive
power
source
Symptoms resulting from wrong connection
• Abnormal motion
•
Nomotion
• OnlyPan
motor
operates
• Faulty
operation
of
the
presser
plate,
presser
foot,
thread
wiper
components,
main
presser,
thread
trimming ,
thread
releasecomponents
• Stepout
in
Xand Y
axes
• Unusual noises
of
X-drive
andY-drive
pulse
motors
Start/stopcontrol currents
for
• Abnormal rotationspeed
of
the
pulley
the
machine
+SV
Needlestopposition control,
synchronizationcontrol,and
rotationcontrol signals
..
s-
• Stopoperationfailure
• The pulley
does
not
rotate
• The
machine
sews
at
abnormally
high
speed,
then
stops. (The EMERGENCY
stop
lamp
lights.)
• The machine does
not
stop with
the
needle
at
the
upperposition.
• The pulley rotates,
but
the
feed mechanism
does
not
work
.
