Mitsubishi Melsec-Q Series User Manual page 316

12.2.17 When the BOOT LED is flickering
Refer to the following flowchart when the BOOT LED of the CPU module flickers at programmable controller power-on,
at operation start, or during operation.
Power off the programmable
controller.
Remove the memory card.
Move the DIP switches SW2 and
SW3 of the CPU module to ON.
Power on the programmable
controller.
CPU module hardware fault. Please
consult your local nearest Mitsubishi
or representative, explaining a
detailed description of the problem.
12 - 21
The "BOOT" LED is flickering
Does the "BOOT" LED
turn on?
NO
Figure 12.14 When the BOOT LED is flickering
Completion of automatic write
YES
from memory card to standard
ROM
Perform boot operation from
standard ROM.