User`s manual

Troubleshooting Troubleshooting
MELSEC System Q, Hardware 11 – 11
11.2.8 When the RUN LED has turned off
* For the Basic model QCPU, use the RUN/STOP/RESET switch for operation.
The RUN LED has turned off
refer to section 11.2.10 (ERR. LED
has turned on or is flickering)
Please consult your local Mitsubishi
service center or representative,
explaining a detailed description of the
problem.
1) Programmable controller part fault/
poor connection between the
module and base unit
2) Excessive noise generatio
Is ERR. LED on/flickering?
Reset the CPU module
Set the CPU module's RUN/STOP
switch* to RUN and enter to the
monitor mode with the GX (IEC)
Developer to be operated.
RUN LED is on
RUN" LED does not
turn on
Possible cause is a sequence program
error.
Set the CPU module's RUN/STOP
switch* to STOP and write END to
address 0 with the programming
device.
Check the program and modify the
program error location.
Connect a surge suppression circuit,
such as CR, to the noise source.
case of
1)
case of
2)
YES
NO
Completed
Can RUN LED turn on?
YES
NO
Is the POWER LED
of the power supply module on
in green?
YES
NO
POWER LED is off:
refer to section 11.2.4
POWER LED is on in red:
(redundant power supply modules
only):
refer to section 11.2.6
RUN LED is
on
RUN LED is
off