JUKI LK-1900AN Engineer's Manual page 119

Trouble
2. Key malfunction on the operation panel
3. Error E007
Machine lock
LED3 on SDC board: Flashing 1 times
4. Error E030
Needle bar up position displacement
5. Error E302
Head tilt error
6. Error E303
Main shaft motor Phase Z sensor error
LED3 on SDC board: Flashing twice
Cause (1)
2-1) No signal transmis- 1-A) Input circuit is out of order.
sion
3-1) The main shaft motor 1-A) The motor connector is dis-
of the sewing machine
cannot rotate.
1-B) The mechanism is locked.
1-C) The driver circuit is out of
4-1) Displacement of the 1-A) The stop position is inad-
up position
5-1) Detector switch con- 1-A) Connector CN67 of the INT
tact open.
1-B) The switch cord is broken.
1-C) The safety switch is broken.
1-D) The switch does not function.
6-1) Z signal (main shaft 1-A) The encoder cord is broken
motor) does not enter.
1-B) The detector circuit is out of
Cause (2)
connected or broken.
order.
equate.
board is disconnected.
or out of order.
order.
Check and corrective measures
Replace the PANEL board.
Check CN16 of the SDC board to see if there
is any disconnection.
Check the mechanism and look for the sec-
tion that is particularly overloaded or whether
screws are loose.
Replace the SDC board.
Try to turn the main shaft by hand. Check if
there is any particular heavy load.
Disconnect CN16 and check the resistance
value among pins. Replace the motor, as
required.
Check CN67 of the INT board.
Check it by means of a circuit tester.
Replace the switch cord.
Check whether the terminal leads are broken
or the switch turns ON/OFF correctly.
Confirm the mounting condition of the switch.
Confirm whether each signal is delivered to
CN14 of the SDC board. In the case of en-
coder error, replace the motor as a whole.
[See the Servo Motor Circuit Diagram.]
Replace the SDC board.