Mitsubishi Electric MELSERVO-J4 Instruction Manual Trouble Shooting page 72

1. TROUBLESHOOTING
Description
The display shows "b##".
(Note)
The display shows "off".
The display turned off.
The servo motor does not
operate.
Note. ## indicates axis No.
Possible cause
Test operation mode has
been enabled.
The system has been in the
ready-off state.
Operation mode for
manufacturer setting is
enabled.
The external I/O terminal
was shorted.
The control circuit power
supply is not applied.
The voltage of the control
circuit power supply has
dropped.
The connection of the servo
motor is incorrect.
The servo motor power
supply cable was connected
to a servo amplifier of other
axis.
The servo-on command was
inputted with main circuit
power supply off.
An alarm or warning is
occurring.
The system has been in the
test operation mode.
The motor-less operation has
been enabled.
The torque is insufficient due
to large load.
An unintended torque limit
has been enabled.
Check result
Test operation setting switch
(SW2-1) is turned on.
Check if the servo ready
state is off with the servo
system controller.
Check if all of the control axis
setting switches (SW2) are
on.
When the display is on by
disconnecting the following
connectors, check if the
disconnected cable wire is
shorted.
[A]: CN1, CN2, CN3
[B] [WB] [RJ010]: CN2, CN3
Check if the control circuit
power supply of the servo
amplifier is off.
Check if the voltage of the
control circuit power supply
dropped.
Check the wiring of U, V, and
W.
Check if the encoder cable
and servo motor power
supply cable are connected
to the same servo amplifier.
Check if [AL. E9] is
occurring.
Check if an alarm or warning
is occurring.
[A]: Check if the lower right
point is flickering.
[B] [WB] [RJ010]: Check if
the test operation setting
switch (SW2-1) is on (up).
[A]: Check the [Pr. PC60]
setting.
[B] [WB] [RJ010]: Check the
[Pr. PC05] setting.
Check instantaneous torque
using status display (only [A])
or MR Configurator2 if the
load exceeds the maximum
torque or torque limit value.
Check if the torque limit is
enabled.
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Action
Turn off the test operation
setting switch (SW2-1).
Turn on the servo-on signals
for all axes.
Set the control axis setting
switches (SW2) correctly.
Review the wiring of I/O
signals.
Turn on the control circuit
power.
Increase the voltage of the
control circuit power supply.
Connect it correctly.
Connect the encoder cable
and servo motor power
supply cable correctly.
Turn on the main circuit
power.
Check the content of the
alarm/warning and remove
its cause.
Cancel the test operation
mode.
Disable the motor-less
operation.
Reduce the load or use a
larger capacity servo motor.
Cancel the torque limit.
Target
[B]
[WB]
[RJ010]
[B]
[WB]
[RJ010]
[A]
[B]
[WB]
[RJ010]
[A]
[B]
[WB]
[RJ010]