Epson ET-8550 White Ink Line Not Printing - Troubleshooting Clogged Tubes and Damper Issues

Question:
I have an Epson ET-8550 printer, and everything prints fine except the white ink. I followed the unclogging techniques shown in your video, but one of my white ink lines has resistance while the other feels loose and empty. Could this be causing the problem? I've tried all cleaning methods, but that white line still won't print even though the tanks are full. What could be wrong?

Answer:

Now, regarding your Epson ET-8550 and the white ink line not printing: based on your description, the issue most likely lies in air blockage or partial clogging within the ink delivery system, particularly the damper assembly or the ink line itself.

1. Understanding the Resistance in Ink Lines

When you feel resistance in one ink line and none in the other, that's an important diagnostic clue.

• The line with resistance usually indicates that ink is present and the line is filled properly.

• The line with no resistance suggests that air is trapped somewhere between the ink tank and the printhead-commonly at the damper or inside the tube.

In the ET-8550 (and similar EcoTank printers), the white ink conversion often makes the system more sensitive to clogs because white pigment ink is thicker and settles faster. Even a small air pocket can stop ink flow entirely.

2. Possible Causes

Here are the most likely causes of your issue:

• Air trapped inside the ink tube: This happens when the ink line isn't fully primed. Air pockets prevent pressure from reaching the printhead, making that channel inactive.

• Clogged damper or filter: The damper acts as a mini reservoir before ink enters the printhead. Over time, pigment particles can accumulate, blocking the fine mesh inside.

• Printhead internal clog or partial delamination: If you've tried multiple cleaning cycles with no success, it's possible the white channel inside the printhead is partially delaminated or internally clogged. White pigment ink can dry quickly and harden if left unused.

• Overfilled or contaminated tank: Even if the tank is full, if the vent is blocked or ink viscosity is off, proper suction cannot form.

3. Recommended Steps to Fix the Issue

Here's what you can try before considering part replacement:

1. Re-prime the white ink line manually:
   Disconnect the white ink line at the damper and gently pull ink through using a syringe (avoid high pressure). If the line fills smoothly, you're restoring proper pressure. If it resists, you may have a clog between the tank and damper.

2. Clean or replace the damper:
   If one line has resistance and the other doesn't, it's often the damper that's blocked. Replacing or flushing the damper with cleaning solution can help reestablish balanced ink flow.

3. Check the tank vent caps:
   Make sure the white ink tank vent is open and unclogged. A closed vent prevents ink flow by creating a vacuum.

4. Avoid excessive power cleaning:
   Running multiple power cleans can overheat and damage the printhead. Instead, use manual ink pulling through the waste line or damper to prime the channel safely.

5. Print frequently:
   Once the flow is restored, print a few test patterns daily to keep the white ink circulating. White pigment ink should never sit idle for long periods.

4. Long-Term Prevention

White ink printers need more frequent maintenance due to sedimentation. Shake your white ink tanks regularly (every few days) and perform nozzle checks to spot early flow issues. Keep the humidity around 40-60% to prevent premature ink drying inside the printhead.

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 (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis, so it might take a few weeks before we can get your printer in for diagnosis. Our services cover both full printer and part-specific repairs with clear instructions. However, since our rates might not be the lowest, we recommend trying self-help first.

You can start by exploring our YouTube channel (https://youtube.com/@bchtechnologies) and use the search icon next to "About" to find specific topics. We have hundreds of videos from over nine years, and YouTube's search function will help you locate relevant guides quickly. It may even suggest other useful videos from related channels.

Thank you once again for reaching out and for your patience. We truly appreciate your support and interest in our content-it's customers like you who help us continue improving and innovating for the printing community.