User`s manual

Troubleshooting Troubleshooting
MELSEC System Q, Hardware 11 – 7
11.2.3 When the MODE LED is flickering
Refer to the following flowchart when the MODE LED of the CPU module flickers at program-
mable controller poweron, at operation start or during operation.
The MODE LED is flickering.
Can MODE
LED turn on?
Set the RESET/L.CLR switch to the
neutral position.
Completed
Hardware fault
Execute operation checks in due order,
starting with the minimum system where
the power supply module and CPU module
are mounted on the main base unit.
For the module that does not operate, ple-
ase contact your local Mitsubishi service
center or representative, explaining a
detailed description of the problem.
Have the forced ON/OFF
settings been made?
Is the CPU module
RESET/L.CLR switch in
the neutral position?
NO
Neutral position
YES
RESET position
YES
NO
Can MODE
LED turn on?
YES
NO
Cancel forced ON/OFF