How to Handle Persistent Nozzle Gaps on Epson WF-3620 and WF-7210 Printers After Repeated Cleaning

Question:
I've learned a lot from your YouTube videos about cleaning Epson printheads. Your tutorials even gave me the confidence to remove the printhead from my printer for easier cleaning. I own a WF-3620 and a WF-7210, along with two more WF-3620s in the family. I've tried several methods-ultrasonic cleaning, soaking the printheads in cleaning solution, rubbing alcohol, and distilled water, even letting them sit overnight or for a week. But I still get nozzle checks with missing segments here and there. I'm very interested in your TMS Printhead Maintenance System (as shown in this YouTube video (https://www.youtube.com/watch?v=YKmx-zBeO0A&t=415s)). Would that system help restore my printheads?

Answer:

1. Understanding the Limits of Cleaning on PrecisionCore Printheads

The Epson WF-3620 and WF-7210 printers use Epson's PrecisionCore printhead technology, which consists of thousands of microscopic nozzles in piezoelectric chambers. While this design delivers high-quality output, it's also one of the most fragile printhead types Epson has ever produced. Unfortunately, these printheads do not tolerate aggressive cleaning well.

When you perform multiple ultrasonic cleanings or prolonged soaking-especially with alcohol or strong cleaning solutions-there's a significant risk of damaging the piezo elements that control ink ejection. Once a nozzle cell is damaged, it no longer fires ink properly, and what looks like a "stubborn clog" is actually a permanent loss of function.

In short, if certain lines in your nozzle check remain missing even after days or weeks of cleaning, the problem is very likely not a clog at all but electronic or mechanical cell damage within the printhead.

2. Why the TMS Printhead Maintenance System Won't Work on WF-3620/WF-7210

The TMS (Total Maintenance System) featured in our videos was designed for printheads that have accessible ink ports and durable channel structures-mainly models like the L1800 or certain XP series printers. Unfortunately, the WF-3620 and WF-7210 printheads don't share the same structure. Their internal chambers are sealed, and their nozzles are smaller and more delicate.

We currently don't have a TMS system compatible with the WF-3620 or WF-7210, and I don't plan to develop one due to the limited market and the high risk of further damage. These printers are also considered older models, and Epson has since shifted away from supporting them with replacement parts or firmware updates.

3. The Best Path Forward

If your printhead is already partially firing and only missing small segments, the best approach at this stage is to stop further physical cleaning and instead keep using the printer regularly. Running frequent prints helps maintain ink flow and prevents remaining functional nozzles from drying.

If, however, entire color channels have stopped printing, replacement of the printhead may be the only long-term solution. Because Epson's firmware is strict about head pairing, replacing it can sometimes require resetting or reprogramming the printer's EEPROM chip-another reason why many service centers are reluctant to repair these models.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. So, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service through our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, our operations are first-come, first-served, so it may take a few weeks before we can schedule your printer drop-off. Our services are structured to repair full printers or specific parts, with clear instructions on how to proceed. However, we understand that our rates may not be the most economical, so we highly recommend trying self-help resources first. You can start by browsing our YouTube channel homepage (https://youtube.com/@bchtechnologies). Use the search icon next to "About" on the top menu to find videos related to printhead care, ink flow restoration, or nozzle maintenance.

Thank you again for your question and for your continued support of BCH Technologies. Your enthusiasm for understanding printer mechanics and your persistence in achieving perfect nozzle checks truly embody the spirit of DIY repair, and we're honored to be a part of your learning journey.