To prepare the USB thumb drive for an AltBoot restore, create an ALTBOOT folder, in the root directory. The folder name must be all uppercase. Next, using Notepad or similar utility, create a zero-length file in the ALTBOOT folder called FORCED_UPGRADE with no extension. Again, this file must reside in the ALTBOOT folder and be named exactly as shown. Finally, copy the latest firmware file (*.dlm) to the ALTBOOT folder.
Turn the printer Off.
Insert the prepared USB thumb drive in the USB Port on the printer’s rear panel.
Turn the printer On. The printer reads the USB port and begins the restore process.
The splash screen displays the ENERGY STAR logo while the printer reads the thumb drive.
The restore process begins with Check Firmware Version being displayed.
Next, the Software Upgrade screen is displayed. Depending on the system configuration (Trays, Finisher) the process can require approximately 20 minutes. The Software Upgrade screen changes to reflect the current subsystem being restored.
After the firmware update process is complete, the AltBoot Complete screen is displayed instructing you to remove the USB thumb drive.
Remove the USB thumb drive from the printer’s USB Port.
Wait for the printer to reboot and return to Ready To Print.
I have a 8900 that got in a bootloop state after a sucessful firmware upgrade.
Tried several times with different USB sticks, different firmware versions, forced upgrades, different hdd also. The firmware updates always work and get to the end and says to press 0 to reboot but the machine always fail to boot (green boot screen, 2 minutes later a white screen flash, black screen and back to the start).