Chapter 3 Troubleshooting; Troubleshooting With The Leds; When The Run Led Turns Off; When The Err Led Turns On - Mitsubishi Electric MELSEC iQ-RX40NC6B Application User's Manual

3
TROUBLESHOOTING
3.1

Troubleshooting with the LEDs

When the RUN LED turns off

Check item
Check whether power is supplied.
Check whether the capacity of the power supply module is enough.
Check whether the module is mounted properly.
Cases other than the above

When the ERR LED turns on

Check item
Check whether any errors have occurred.

When the ALM LED turns on

Check item
Check whether any alarms have occurred.

When an I/O LED does not change

Check item
Check whether "Switching display of input status and alarm (1 second
intervals)" or "Always display abnormal occurrence points" is set in "LED
display setting when error occurred" of the input module with diagnostic
functions.
Check whether "Switching display of output status and alarm (1 second
intervals)" or "Always display abnormal occurrence points" is set in "LED
display setting when error occurred" of the output module with diagnostic
functions.
3 TROUBLESHOOTING
60
3.1 Troubleshooting with the LEDs
Action
Check that the supply voltage to the power supply module is within the rated
range.
Calculate the current consumption of mounted modules, such as the CPU
module, I/O modules, and intelligent function modules, to check that the
power capacity is enough.
Check the mounting state of the module.
Reset the CPU module and check that the RUN LED turns on.
If the RUN LED still remains off, the possible cause is a failure of the module.
Please consult your local Mitsubishi representative.
Action
Check 'Latest error code' (Un\G2560), and take actions described in the list of
error codes.
Page 68 List of Error Codes
Action
Check 'Latest alarm code' (Un\G2564), and take actions described in the list
of alarm codes.
Page 70 List of Alarm Codes
Action
Check the current setting of "LED display setting when error occurred".