Ctl Pcb; Error Codes - JUKI SC-921 Instruction Manual

3) Be sure to use a fuse with the designated capacity.
❸ : 6.3 A/250 V Time-lag fuse (Solenoid power circuit protection fuse)
Part number: KF000000030
4) Close the cover of the control box.

3. Error codes

In case of the following, check again before you judge the case as trouble.
Phenomenon
When tilting the sewing machine, the
buzzer beeps and the sewing machine
cannot be operated.
Solenoids for thread trimming
Solenoids for thread trimming, reverse
feed, wiper, etc. fail to work. Hand
lamp does not light up.
Even when depressing the pedal im-
mediately after turning ON the power,
the sewing machine does not run.
When depressing the pedal after de-
pressing the back part of pedal once,
the sewing machine runs.
The sewing machine does not stop
even when the pedal is returned to its
neutral position.
Stop position of the sewing machine
varies (irregular).
Presser foot does not go up even
when auto-lifter device is attached.
Touch-back switch fails to work.
UP position move fails to work when
all lamps on the panel light up.
Sewing machine fails to run.
❸
Cause
When tilting the sewing machine
without turning OFF the power switch,
Action given on the left side is taken
for safety sake.
When the fuse for solenoid power pro-
tection has blown out
Neutral position of the pedal has var-
ied.
(Neutral position may be shifted when
changing spring pressure of the pedal
or the like.)
When tightening the screw in the
handwheel is forgotten at the time of
adjustment of needle stop position.
Auto-lifter function is OFF.
Pedal system is set to KFL system.
Cord of auto-lifter device is not con-
nected to connector (CN37).
Presser foot is going up by auto-liter
device.
Auto-lifter device is not attached. How-
ever, auto-lifter function is ON.
The mode is in the function setting mode.
The switch on the CTL p.c.b. is
pressed by the bound cords and the
aforementioned mode resulted.
Motor output cord (4P) is disconnected. Connect the cord properly.
Connector (CN30) of motor signal cord
is disconnected.
– 45 –

(2) CTL PCB

1) Open the cover of the control box.
2) Pick up the glass section of fuse ❸
mounted on the CTL PCB with fingers
to remove it.
(Caution) In order to protect against the
possibility of electric shock,
it is necessary to remove
the fuse after LED ❷ of the
PWR PCB has totally gone
off.
Corrective measure
Tilt the sewing machine after turning
OFF the power.
Check the fuse for solenoid power
protection.
Execute the automatic neutral correc-
tion function of the pedal sensor.
Securely tighten the screw in the
handwheel.
Select "FL ON" by auto-lifter function
selection.
Change the jumper to PFL setting to
lift the presser foot by depressing the
back part of the pedal.
Connect the cord properly.
Operate the switch after the presser
foot lowered.
Select "FL OFF" when auto-lifter
device is not attached.
Remove the under cover. Bundle
the cables by routing them accord-
ing to the normal routing method as
described in the Instruction Manual.
Connect the cord properly.