11 - 9 11 - 9
MELSEC-Q
11 TROUBLESHOOTING
11.2.10 Flowchart for when the "BOOT" LED is flickering
The following shows the flowchart to be followed when the "BOOT" LED of the CPU
module flickers at PLC power-on, at operation start or during operation.
"BOOT" LED flickering
Is the "BOOT" LED turned on?
Power off the PLC.
CPU module hardware fault.
Please consult your local Mitsubishi
service center or representative,
explaining a detailed description
of the problem.
Remove the memory card.
Power on the PLC.
Move the DIP switches SW2 and
SW3 of the CPU module to ON.
NO
Completion of automatic write from
memory card to standard ROM
Perform boot operation from
standard ROM.
YES