31,004.40:6909: it's a mechanical initialization jam error. Pull out the paper tray to make sure it doesn't have a jam. Try also to manually feed some heavy paper or card stock through the printer to make sure the sensor in the preheater isn't stuck.
39,002.40 : DRAM test failure.
39,012.40:56208: "Cycle the power" and if that does not work replace the document feeder.
39,012.41: Document Feeder Optical Failure. Replace the document feeder.
4,0XX.6x: Process Control Software Fault.
- Reset NVRAM and then retest.
- Ensure ground integrity for the system
- Replace the EEPROM chip.
- Reboot the system.
- From the System Setup menu, go to "Information", "Troubleshooting"
- Service Tools menu.
- With the cursor at the top of the Service Tools menu, press both the Up Arrow
- and Down Arrow buttons to display the Hidden Service menu.
- Reset NVRAM is in there.