JUKI MOL-254 Engineer's Manual page 229

No. Phenomenon
6 Alarm No. [AL-13] is displayed Fan filter clogs with dust.
on the operation box panel.
Fan motor fails to rotate.
7 Thread breakage detection Thread breakage detection error appears although needle thread
operation is defective. is not trimmed.
Thread breakage detector fails to work although needle thread
is trimmed.
8 Data setting is not posiible.
Sewing data [1*] can refer, but setting or change cannot be
performed.
Adjustment data [B*] can refer, but setting or change cannot be
performed.
9 Machine head is located at normal position, bur error cannot be
Alarm No. [AL-32] is displayed
released.
on the operation box panel
when pressing the start switch.
10
B e l t l o o p s p l i c e c u t t i n g Splice cutting section is supplied as normal loop.
procedure is abnormal.
Splice border line is sometimes supplied.
11 Belt loop length is different from The length becomes sometimes shorter than the set value.
the set value.
Belt loop which is slack in the center is supplied.
12 Alarm No. [AL-44] is displayed Alarm remains and the display cannot return to the normal state.
on the operation box panel
immediately after turning ON
the power.
Detailed state
Clean the fan motor filter and the exhaust slot.
It is considered that connector CN34 is disconnected, or the cable has broken.
Correctly connect it.
Check the connection (resistance value) between thread breakage detector plate
and machine head (FG). Adjust so that the resistance value between machine
head and the detector plate is 0Ω when the thread take-up spring comes in
contact with the detector plate and it is infinite when the thread take-up spring
leaves from the detector plate.
Re-adjust as described above. Check the setting whether thread breakage
detection is effective. (ON the upper SW3 of DIP switches on the side of the
operation box panel)
It is considered that connector CN16 is disconnected or the cable has broken.
Correctly connect it.
Data lock function is working when "DATA LOCK" is displayed at the bottom of
the screen. Hold pressing the standard screen key for 10 seconds or more to
release the data lock.
Data lock function is working when "DATA LOCK" is displayed at the bottom of
the screen. Hold pressing the standard screen key for 10 seconds or more to
release the data lock.
Adjustment screen protect is performed when there is a padlock mark indication
at the lower right of the screen. Turn ON the upper SW2 of DIP switches on the
operation box panel to release the protect.
It is considered that connector CN115 or CN12, or the cable has broken. Correctly
connect it.
There is a possibility of maladjustment. Perform again the setting of belt loop
splice detection with the loop currently used.
Check whether there is any place where a load is applied to the belt in the
supplying route of the belt loop. (Especially, check whether the splice section is
being caught in some place or there is any slide at motor gear section making
use of the step operation function.)
Re-check the splice cutting setting [BD] and {BE] and set them to the proper
values.
Check whether there is any place where a load is applied to the belt in the
supplying route of the belt loop. (Especially, check whether the splice section is
being caught in some place or there is any slide at motor gear section making
use of the step operation function.)
Check whether the fullness setting is proper.
It is considered that the MAIN circuit board is damaged. Replace the circuit
board.
Checking point and corrective measure Replacing part
MAIN circuit board
Fan motor
Thread breakage detection
device
Thread breakage detection
device
MAIN circuit board
Head detection SW
Loop thickness sensor
Loop feed/pull-out stepping
motor
MAIN circuit board
MAIN circuit board