How to Fix White Ink and Banding Issues on a DTF-Converted Epson ET-8550 After Downtime

Customer Question:
I have an Epson ET-8550 that I converted for DTF printing. After returning from a 10-day vacation, the white ink stopped printing correctly, and my designs are coming out with lines instead of a smooth image. Do you have a video that shows how to disassemble the machine and remove the printhead so that I can test the suction with a cleaning solution? Also, if I want to connect a CISS system, can I route the tubes through the original tanks instead of cutting into the side of the printer?

Answer:

Why Your ET-8550 Developed Issues After a 10-Day Pause

It’s very common for converted printers—especially those using white DTF ink—to struggle after periods of inactivity. Here’s why your printer is now printing white ink inconsistently and showing lines:

• White Ink Sedimentation: White pigment ink settles faster than regular ink. After just a few hours, the pigment can begin to clump inside tubes or the printhead, especially without agitation or regular printing.

• Dried Nozzles: Idle time allows moisture to evaporate from the printhead nozzles, which can lead to clogs.

• Reduced Suction Efficiency: Even if the nozzles are semi-clear, weak sealing from the capping station can prevent effective suction during cleanings.

• Ink Starvation Symptoms: Banding and visible lines usually indicate one or more clogged nozzles or air bubbles obstructing flow.

How to Access and Test the Printhead

Yes, we have detailed walkthroughs that show how to disassemble your Epson ET-8550. One of the best resources is our video:
Advanced ET-8550 DTF Conversion: Install Ink Delivery System - Complete Course (Part 1)
(https://www.youtube.com/watch?v=jyu6bgWe5sQ)

This video guides you through the process of accessing the printhead and preparing the system for deep cleaning or tubing installation. For full troubleshooting, we also suggest watching our DTF Maintenance and Printhead Cleaning videos, which cover:

• Safe printhead removal

• Soaking techniques for clearing nozzles

• How to backflush the cleaning fluid

• Capping station testing and evaluation

Try the Syringe Suction Test Before Disassembly

Before going straight into removing the printhead, you can try this diagnostic:

1. Let the Printer Dock the Printhead: Power it on and allow the printer to park the head on the capping station.

2. Attach a Syringe to the Waste Line: Use the waste ink tube behind the printer.

3. Gently Draw 1.5–2ml of Air:

   • Smooth Pull + Crinkling Sound: Nozzles are mostly clear.

   • No Resistance: Likely a faulty capping station seal.

   • Complete Blockage: Likely fully clogged nozzles.

Holding suction for 10 seconds helps reveal any air leaks or obstructions in your ink path.

Installing a CISS Without Cutting the Side

Yes, you can route your Continuous Ink Supply System (CISS) tubes through the existing tank ports on the ET-8550 without modifying the printer's exterior. Here’s how:

• Open the ink tank lid and remove the rubber septum plugs from under the tank caps.

• Gently insert your ink tubes into the ports; a snug fit is essential to prevent air leaks.

• If your model has spring-loaded ink sensors, you may need to bypass them with resistors or electrical tape to avoid “low ink” errors.

• This method is cleaner, safer, and more reversible than side-mounting or drilling.

If You Decide to Remove the Printhead

If suction fails or deeper cleaning is needed, here are the best practices:

• Label All Ribbon Cables: Take pictures to ensure accurate reassembly.

• Soak Only the Nozzle Inlets: Use a lint-free container and submerge just the metal nozzle side (avoid wetting the PCB).

• Use Gentle Suction Only: never apply pressure, as it can force debris further into the head.

• Avoid Harsh Chemicals: Use only recommended cleaning fluids designed for pigment or DTF ink systems.

A Note on DTF Maintenance

White ink clogs and nozzle drying are the most common reasons DTF-converted printers fail. Regular agitation of white ink and weekly nozzle checks—even during idle weeks—are essential. Many owners think one issue (e.g., banding) is isolated, but often, it's part of a chain reaction involving pressure loss, air leaks, and damper wear. It’s why we sometimes recommend full diagnostics if multiple issues appear.

Addressing printer issues can be a complex process due to the hands-on and mechanical nature of the problems. Therefore, we are not able to provide remote troubleshooting or repair support. However, we do offer in-person printer evaluations and repairs through our diagnostic service facility (https://bchtechnologies.com/printer-repair-service). Please note that we work on a first-come, first-served basis, and it may take a few weeks before we can accept your drop-off. While our repair rates may not be the lowest, we do offer the option to repair individual components or the entire printer. If you're more inclined toward DIY repair, we highly encourage exploring our resources on YouTube. Visit our channel homepage (https://youtube.com/@bchtechnologies) and use the magnifying glass icon to search for specific topics. With over nine years of content, using the built-in YouTube search is the best way to find what you need efficiently.

Thanks again for reaching out—we truly appreciate your engagement and your trust in BCH Technologies to help with your printer journey. Good luck with the syringe pull test and your setup, and don’t hesitate to circle back if you need more support or parts.