Appendix 3
If any function of the CPU module does not operate as designed, perform troubleshooting by checking the following items. If
the ERROR LED or USER LED is on or flashing, eliminate the error cause using the engineering tool.
When the POWER LED of the power supply module turns off
For troubleshooting, refer to the following:
MELSEC iQ-R Module Configuration Manual
When the READY LED of the CPU module turns off
Check the following:
Check item
Check if the CPU module is mounted on the main base unit properly.
Check if the READY LED of another module is on.
Check if the READY LED turns on when the power supply module is replaced
and the power is restored to the system.
(Check the LED status after the power supply module on the extension base
unit is also replaced.)
Check if the READY LED does not turn on even after the power supply
module is replaced and the power is restored to the system.
(Check the LED status after the power supply module on the extension base
unit is also replaced.)
Check if the system was powered on immediately after power-off.
If the READY LED of the CPU module does not turn on even after the items above are checked and the actions are taken, the
possible cause is a hardware failure of the power supply module. Please consult your local Mitsubishi representative.
APPX
798
Appendix 3 Troubleshooting by Symptom
Troubleshooting by Symptom
Action
Remove the CPU module from the main base unit, and mount it back on the
main base unit.
A major error has occurred in the CPU module. Replace the CPU module.
An error has occurred in the power supply module(s) before the replacement.
Replace the power supply module.
An error has occurred in a module other than the power supply module.
Repeatedly supply power to the system, returning the modules back to the
system one by one.
The last module mounted immediately before the READY LED turned off has
been failed. Replace the module.
Wait for five seconds or longer after power-off and power on the system again.