Flashing Sequence - Lexmark X422 Laser MFP Service Manual

7001–001

Flashing sequence

Once the system has terminated all activities, previous described,
the following flash sequence begins:
1. The panel will display progress as the flash data is read over
one of the host interfaces.
2. After a data segment is read in, a CRC is computed. The
success or failure of that CRC is posted on the panel.
– If the CRC fails, the device automatically reboots after a few
seconds.
3. Steps 1 and 2 are repeated for each segment of data in the
flash file. (There are generally two.)
4. After all data is read into memory (assuming no errors have
occurred), the Flash Kernel takes over control, and all other
applications are no longer able to execute.
5. The Flash Kernel operates the panel in text mode to display
progress as the NAND Flash is programmed.
Note: The "DO NOT POWER OFF" message (translated)
should remain intact on the bottom half of the panel.
6. Once all partitions have been programmed, the device
automatically reboots.
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Service Manual