JUKI SC-920 Instruction Manual page 50

No. Description of error detected
E704(*) System version mismatch
E730 Encoder failure
E731 Motor hole sensor failure
E733 Inverse rotation of motor
E799 Thread trimming operation
time-out
E808 Solenoid short circuit
E809 Holding motion failure
E810 Solenoid current abnormality • Solenoid rare short-circuit.
E811 Abnormal voltage
E906 Operation panel transmis-
sion failure
E924 Motor driver failure
E942 Faulty EEPROM
* The error number attached with an asterisk (*) is displayed only in the case a fault occurs when the IP/IT pan-
el is connected to the sewing machine.
Cause of occurrence expected
• The system version is different from the
correct one in the initial communication.
• When the motor signal is not properly
inputted.
• This error occurs when the motor is run-
ning at 500 sti/min or more in the opposite
direction of that of rotation indication during
motor is running.
• The thread trimming control operation is
not completed within the predetermined
time (within three seconds).
• Solenoid power does not become normal
voltage.
• Solenoid is not changed over to holding
motion.
• When voltage higher than guaranteed one
is inputted.
• 200V has been inputted to SC-920 of 100V
specifications.
• JA : 220V is applied to 120V box.
• CE : 400V is applied to 230V box.
• When voltage lower than guaranteed one
is inputted.
• 100V has been inputted to SC-920 of 200V
specifications.
• JA : 120V is applied to 220V box
• Inner circuit is broken by the applied over-
voltage
• Disconnection of operation panel cord.
• Operation panel has broken.
• Motor driver has broken.
• Data cannot be written on the EEPROM.
– 48 –
Items to be checked
• Re-write the system version to the one that
can be used with the operation panel.
• Check the motor signal connector (CN30) for
loose connection and disconnection.
• Check whether the motor signal cord has bro-
ken since the cord is caught in the machine
head.
• Check whether the inserting direction of the
motor encoder connector is wrong.
• Check whether the machine head corre-
sponds with the machine type setting.
• Check whether the main-shaft motor encoder
wire is connected incorrectly.
• Check whether the main-shaft motor wire for
power supply is connected incorrectly.
• Check whether the machine head actually
installed is different from the machine head
selection.
• Check whether the motor-pulley diameter
does not match its setting (effective diame-
ter).
• Check whether the belt has slackened.
• Check whether the machine head cord is
caught in the pulley cover or the like.
• Check whether the solenoid is abnormally
heated. (CTL circuit board asm. Circuit is
broken.)
• Solenoid resistance.
• Check whether the applied power voltage is
higher than the rated voltage + (plus) 10% or
more.
• Check whether 100V/200V changeover con-
nector is improperly set.
In the aforementioned cases, POWER p.c.b
is broken.
• Check whether the voltage is lower than the
rated voltage - (minus) 10% or less.
• Check whether 100V/200V changeover con-
nector is improperly set.
• Check whether fuse or regenerative resis-
tance is broken.
• Check the operation panel connector (CN38)
for loose connection and disconnection.
• Check whether the operation panel cord
has broken since the cord is caught in the
machine head.
• Turn the power OFF.