Canon iR4570 Series Service Manual page 179

The machine will indicate an error code if it finds a fault while running the program.
- Boot Program (interval 2)
When the self-diagnosis program ends normally, the CPU on the main controller PCB executes the boot program.
The program is used to read the system software from the HDD to write it into the image memory (SDRAM).
<Image Memory (SDRAM) Area> (interval 3)
The system software written by the boot program initializes the various functional blocks (e.g., I/F settings of the
main controller).
When all the foregoing ends normally, the machine becomes ready to accept a job
(i.e., the control panel shows the Operation screen, and the LED on the Start key changes from red to green).
Progress bar
1 2 3
F-4-10