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ELECTRICAL SYSTEMS TROUBLESHOOTING
* When measuring resistance, always turn the power off and disconnect the connector to be measured
from the circuit board before taking the measurement.
* Refer to the figures for where to check.
CONDITION
PROBLEM SYMPTOMS
COUNTERMEASURES
1. Power is ON
but the buzzer
does not sound
and nothing is
displayed in the
LCD.
1) When the power switch is ON, is the
resistance between both ends less than
1
Ω
?
2) Disconnect the output connector (CN1)
from the power supply PC board; is the
voltage between terminals 1-2, and 3-4
normal?
Between 1-2 ......................24 to 31 V DC
Between 3-4 ......................13 to 18 V DC
3) Is the fuse blown?
4) Other
1) Replace the power supply unit assembly.
2) Replace the power supply unit assembly.
3) Replace the fuse (after correcting the
cause of the blown fuse).
4) Replace the main PC board assembly.
2. Pulse motors
do not correctly
detect the
home position
after the power
is turned on
and the needle
is in the up
position.
1) Is there the normal resistance between
the following pins of the connector of the
pulse motor that does not detect the
home position?
X (CN16)....Between 1-2, 3-4
→
Approx.
Ω
Y (CN17)....Between 1-2, 3-4
→
Approx.
Ω
2) The pulse motor only detects the home
position regardless of the needle position.
3) Is the fuse blown?
4) Disconnect the output connector (CN1)
from the power supply PC board; is the
voltage between 1-2 normal?
Between 1-2 ......................24 to 31 V DC
5) X or Y pulse motor will not stop seeking
the home position.
6) Other
1) Replace the defective pulse motor.
2) Replace the NP PC board assembly.
3) Replace the fuse (after correcting the
cause of the blown fuse).
4) Replace the power supply unit assembly.
5) Replace the X sensor PC board
assembly or the Y sensor PC board
assembly.
6) Replace the main PC board assembly.