How to Backdate Epson XP-640 and WF-2850 Firmware for Chipless Printing

Question:
I've been trying to backdate my Epson XP-640 and WF-2850 printers so I can use third-party chipless firmware. However, every method I've tried from chipless companies fails. It seems Epson has blocked the printers from entering Recovery Mode. Is there any way you can help me backdate the firmware to a chipless version?

Answer:

Now, regarding your Epson XP-640 and WF-2850 firmware issue:
Epson has indeed tightened its firmware protections in recent updates, making it difficult to roll back or modify the firmware for chipless operation. The most recent firmware builds block access to Recovery Mode, preventing standard downgrade methods. However, there are several approaches you can try to resolve this issue:

1. Restart the Printer in Service Mode
   Try entering Service Mode instead of the standard Recovery Mode. This can sometimes allow firmware flashing where normal recovery fails. The process usually involves holding a specific button combination while powering on the printer. For most Epson models, it's often Stop + Left + Down + Power, but this can vary slightly by model.

2. Use Epson's Recovery Firmware Tool
   Download Epson's recovery firmware (sometimes distributed by regional support sites). This tool can overwrite the existing firmware if the printer is detected via USB. Ensure you're using a direct USB connection-wireless connections won't work for firmware recovery.

3. Try WICReset Firmware Rollback
   The WICReset Utility is another potential solution. It includes an option to roll back or reload firmware versions. Connect the printer, select your model, and choose "Firmware Downgrade." Be aware that not all versions are available, and some may fail if Epson's latest updates have locked downgrade capability.

4. Use a Binary Dump (EEPROM Method)
   If all else fails, search for a binary dump file for your specific model (e.g., "bin dump XP640 site:bchtechnologies.com"). Once you locate a reliable file, you can:

   • Build your own EEPROM programmer (or buy one on Amazon).

   • Physically connect to the printer's EEPROM chip.

   • Flash the dump file directly into the memory chip.

   This method requires precision soldering and should only be attempted if you're comfortable handling microelectronics. In some cases, EEPROM corruption can prevent normal operation, so replacing the chip entirely may be the best route.

Please note that some chipless firmware solutions are model- and region-specific, so compatibility is not guaranteed. Epson's recent firmware security updates (especially post-2022 versions) include signature verification checks, which automatically reject modified or unsigned firmware files.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service via our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, our service operates on a first-come, first-served basis, and it may take a few weeks before your printer can be examined. We handle both full repairs and individual part replacements, with clear instructions on how to proceed. While our rates may not be the lowest, we encourage you to explore self-help options online-especially through our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon next to "About" on the channel menu bar to find specific topics. With hundreds of videos spanning nearly a decade, this search function is the quickest way to locate related tutorials.

Thank you again for reaching out and for supporting BCH Technologies. Your curiosity and persistence help us continue developing resources for printer users everywhere.