Epson WF-7720 and WF-7620 Printer Repair: Mainboard and Printhead Issues Explained

Question:
I have two Epson WF-7720 and two Epson WF-7620 printers. The printheads on the 7620 units might still clean up, but one of the 7720s has a faulty mainboard. The printer repeatedly restarts and only stays powered up in recovery mode. Firmware updates appear successful in recovery mode, but after restarting, the update fails. I’ve tested this by swapping the board from another working WF-7720. Are you able to accept mainboards for repair from the UK, or do you have repair facilities there?

Answer:

Based on your description, the issue with your Epson WF-7720 mainboard sounds very much like a faulty EEPROM. The EEPROM is a small memory chip on the mainboard that stores important firmware data. When it becomes corrupted, the printer often exhibits the exact symptoms you described:

• Endless restart loops where the printer fails to boot into normal mode.

• Recovery mode stability, allowing the printer to remain powered on temporarily.

• Firmware update failures—updates appear to install successfully but do not survive a reboot.

The good news is that this is often an easier and more affordable repair than replacing the entire board. Instead of mailing the board to us, you may save money by replacing the EEPROM chip yourself. Here’s what’s involved:

1. Identify the EEPROM – On your Epson WF-7720 mainboard, look for an SOP8 EEPROM chip.

2. Replace the chip – We carry blank EEPROMs that you can match to your board. You can find them by searching “EEPROM” on the BCH Technologies website (https://bchtechnologies.com).

3. Write the firmware – Using an EEPROM programmer, you’ll need to write a good copy of the firmware (often referred to as a binary dump, or BIN file) onto the chip. After installation, the printer should boot normally again.

This method avoids the need for overseas shipping and board-level repairs, which can be costly and time-consuming.

As for your Epson WF-7620 printheads, these may respond well to deep cleaning if the clogging isn’t severe. Printhead clogs can usually be treated with flushing solutions and ultrasonic cleaning. However, if internal nozzles are permanently blocked, replacement may be the only option.

At this time, we don’t have a repair facility in the UK. We do accept mail-in repairs from international customers, but for your specific case, replacing the EEPROM locally is the most efficient solution.

Important Note on Printer Repairs

Addressing printer issues can be a complicated affair since many problems require hands-on work. We are not able to provide remote step-by-step repair support. However, we do offer in-person evaluations and repairs at our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Due to high demand, repairs are scheduled on a first-come, first-served basis, and it may take a few weeks before your printer can be serviced. Our rates are not the lowest, so for many customers, self-help through online resources remains the most practical option. We recommend starting with our YouTube channel (https://youtube.com/@bchtechnologies) and using the search function (magnifying glass icon) to locate videos relevant to your printer model.

Thank you again for your question and for supporting BCH Technologies. We appreciate your engagement and look forward to helping you and other printer users with detailed guidance and resources.