Diagnosing Ink Flow Problems After DTF Conversion: What to Do When a Color Stops Printing

Question:

I've converted my Eldon printer for DTF (Direct to Film) printing using a CISS (Continuous Ink Supply System). After performing multiple head cleans, power cleans, manual flushes, and damper cleanings, the white damper, which was previously clogged, was fixed. But after that repair, all the ink temporarily stopped printing. After further flushing, every color returned except for blue. Do you think the damper needs to be replaced?

 Answer:

Diagnosing the Missing Blue Ink After Damper and Printhead Maintenance

From your description, it sounds like cleaning resolved the initial problem with your white damper, but it led to a larger issue—ink flow stopped completely, followed by a partial return. The fact that every color returned except blue gives us a narrow diagnostic path.

Two Primary Possibilities:

1. Clogged Nozzle on the Blue Channel

2. Poor Seal or Air Leak in the Blue Damper or Tubing

Test the Damper Seal vs. Nozzle Clog

To identify the root cause, we recommend a manual ink draw test with a syringe. This can help determine whether the issue is in the ink supply system or the printhead nozzle.

Here's how:

• Fill a syringe with about half full of blue ink.

• Attach a small plastic tube to the syringe.

• Place the tube on the ink inlet of the blue damper.

• Gently pull the syringe plunger.

What You’re Looking For:

• Strong vacuum resistance followed by ink drawn into the damper suggests that the nozzle is intact and there’s no obstruction.

• Complete vacuum (plunger feels stuck): This implies a possible nozzle clog in the printhead’s blue channel.

• No resistance and air draws easily: The damper is not sealing correctly, allowing air in and preventing ink from pressurizing the line—likely the real issue.

Damper Seal Solutions

Since your printer stopped printing after repairing a clogged white damper and slowly recovered, a bad seal is a likely culprit, especially in systems using OEM Epson dampers with their proprietary washer setup. If a seal isn’t tight, ink can siphon back to the tank, a phenomenon you've observed.

Here are two possible solutions:

• Replace the OEM washer with a thicker one:
  Check out this Epson OEM washer replacement
  [https://bchtechnologies.com/products/6-thick-silicone-washer-gaskets-2-5-mm-for-epson-et-8550-oem-washer-replacement?_pos=1&_sid=d995b38cf&_ss=r]

• Add washer on top of the OEM one to improve the seal:
  Try this additional washer gasket seal pad set
  [https://bchtechnologies.com/products/6-pcs-silicone-washer-gasket-seal-pad-for-epson-et-8551?_pos=3&_sid=5c0969e44&_ss=r]

If you're using aftermarket parts and have converted the printhead to a nipple intake style, a full damper replacement would be the more practical route. A failed or worn damper won’t hold vacuum and may pull air instead of ink, especially in negative-pressure setups like DTF conversions.

A Clue in the Cleaning Video

You mentioned seeing white ink during cleaning cycles, which suggests that the printhead isn't completely clogged or that the white nozzles are still firing to some extent. Observing even partial ink ejection usually leans toward an ink delivery problem (air leak or damper seal) rather than a complete clog.

Final Notes

Printer repairs and conversions are inherently hands-on processes, often requiring trial-and-error and part replacement to resolve issues fully. Unfortunately, we're unable to offer remote troubleshooting or technical support. However, we do provide professional evaluation and repair services through our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Due to demand, services are on a first-come, first-served basis and may take several weeks. Our repair offerings can focus on full-unit restoration or specific component-level issues, with instructions included. Please note that our pricing may not be the lowest in the market, so we encourage self-service repair first when feasible.

We recommend checking out helpful videos through our YouTube homepage (https://youtube.com/@bchtechnologies). Use the search function next to the "About" section on the menu bar to locate guides specific to your printer model or error. We've been uploading for nearly a decade, so search is often faster than browsing.

Thank you again for your question and for being part of the BCH Technologies community. We truly appreciate your commitment to learning and problem-solving!