JUKI LK-1900B series Engineer's Manual

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WARNING :
When it is necessary to open the control box containing electrical parts, be sure to turn the power off and wait for ve minutes or more before opening the cover in
order to prevent accident leading to electrical shock. If the work is performed while the power is ON, never touch other than necessary parts.
Trouble Cause (1) Cause (2) Check and corrective measures
18. Error E903 appears. 18-1) 85V power supply of the SDC
board is not output.
1-A) Fuse F1 of the MAIN board
has blown.
Replace fuse F1 of the MAIN board and measure the resis-
tance value of pins 1-2 of CN31.
If there is short circuit, replace the MAIN board.
1-B) There is no output of the SDC
board.
Disconnect CN31 of the MAIN board and check the output of
the SDC board.
Turn on the power. If DC85V is not generated, replace the
SDC board.
19. Error E904 appears. 19-1) 24V power supply of the SDC
board is not output.
1-A) DC85V is not generated by the
SDC board.
Disconnect CN31 of the MAIN board and check the output of
the SDC board.
Turn on the power. If DC85V is not generated, replace the
SDC board.
1-B) 24V system is out of order. Disconnect CN38 of the MAIN board and check the output of
the SDC board.
If there is no 24V output between pins 1-4, replace the SDC
board.
Measure the resistance value of pins 1-4 of CN38 of the MAIN
board.
If there is short circuit, replace the MAIN board.
20. Error E905 appears. 20-1) Cooling of the SDC board is
not possible.
1-A) Fan does not rotate. Check the status of connections or the adhesion of dust at
CN33 (fan) of the MAIN board.
1-B) Heat dissipation of the element
is not possible.
Check the status that each elements of the SDC board is xed
to heat sink.
21. Error E914 appears. 21-1) The main shaft is not synchro-
nized to the feed mechanism.
1-A) The main motor can not be
rotated normally.
Check whether there is an overload on the main shaft.
Check whether screws of main shaft coupling is loose.
Disconnect CN17 of the SDC board and check the winding
resistance value of main motor.
If there is a problem with the resistance value, replace the
main motor. If there is no problem in the main motor, replace
the SDC board.

JUKI LK-1900B series Specifications

General

Brand	JUKI
Model	LK-1900B series
Category	Sewing Machine
Language	English