Electrical Components - JUKI MOL-254 Engineer's Manual

[3] Electrical components

When the phenomenon has not been corrected after performing the corrective measures referring to the item "Checking point and corrective measure", the circuit board or sensor is considered to be damaged.
Replace the part with one described in the item "Replacing part".
No. Phenomenon
1 Alarm No. [AL-01] is displayed Check the alarm LED on the SDC circuit board.
on the operation box panel
immediately after turning ON 1-time flashing, motor-lock, is displayed.
the power.
(Sewing machine motor fails to
rotate.)
5-time flashing, motor driver element error, is displayed.
6-time flashing, detection of low voltage of power voltage, is
displayed.
8-time flashing, detection of high voltage of power voltage, is
displayed.
10-time flashing, input of motor control method, is displayed.
2 Alarm No. [AL-01] is displayed Check the alarm LED on the SDC circuit board.
on the operation box panel
while the sewing machine 2-time flashing, defective upper dead point sensor, is displayed.
motor is rotating.
( I n c l u d i n g t h e n e e d l e - u p
detection rotation immediately 3-time flashing, detection of defective motor encoder, is
after turning ON the power) displayed.
4-time flashing, detection of defective motor position sensor, is
displayed.
5-time flashing, motor driver element error, is displayed.
7-time flashing, detection of motor control current limitation value,
is displayed.
9-time flashing, defective motor rotation direction, is displayed.
3 Alarm No. [AL-04] is displayed Errors frequently occur after changing the sewing data.
on the operation box panel
while the sewing machine
motor is rotating.
4 Alarm No. [AL-07] is displayed Errors frequently occur after changing the sewing data.
on the operation box panel
while the sewing machine
motor is rotating.
5 Alarm No. [AL10] is displayed Error is not recovered although the specified value of air pressure
on the operation box panel. is supplied.
Error occurs during operation, but is recovered later.
Detailed state
Turn main shaft by hand and remove the mechanical cause if it does not rotate
smoothly.
It is considered that connector CN49 is disconnected or the cable has broken.
Correctly connect it.
It is considered that the circuit board has broken. Replace the circuit board.
Check the operating power and setting of the power changeover tap.
Check the operating power and setting of the power changeover tap.
It is considered that the circuit board has broken. Replace the circuit board.
It is considered that connector CN44 or CN114 is disconnected, or the cable has
broken. Correctly connect it.
It is considered that connector CN43 is disconnected, or the cable has broken.
Correctly connect it.
It is considered that sewing machine main shaft servo motor has trouble.
Check whether the fan motor is rotating, or the filter clogs with dust.
It is considered that a heavy load is applied to main shaft during rotation of the
sewing machine. Check whether there is any torque that produces problem.
It is considered that the sewing machine servo motor has trouble.
Check whether the set value of machine head X-Y drive timing is the standard
value, 50˚. In case of setting of 70˚, re-set the data [CE] to 50.
Check whether the set value of machine head X-Y drive timing is the standard
value, 50˚. In case of setting of 70˚, re-set the data [CE] to 50.
It is considered that connector J78, CN113 or CN8 is disconnected, or the cable
has broken. Correctly connect it.
Supply or adjust air so that the air pressure indicating pointer becomes 0.5 Mpa.
Use air piping method and supply source with which the pointer does not become
lower than 0.4 Mpa during sewing.
Checking point and corrective measure Replacing part
SDC circuit board
SDET sensor
SDC circuit board
Main shaft servo motor
SDET sensor
SDC circuit board
MAIN circuit board
Air regulator