Epson EcoTank ET-2720 Yellow Ink Not Printing: Damper Refills Manually but No Yellow on Test Prints

Question: My Epson EcoTank ET-2720 suddenly stopped printing yellow. Head cleaning doesn't help. When I removed the yellow damper, it was empty-but when I pulled ink through it with a syringe, it filled easily with almost no resistance. Ink seems to flow fine into the damper, yet after reinstalling it, a full-yellow print still comes out blank. What should I check next, and what parts might I need?

Answer: 

Based on your troubleshooting, the most important clue is exactly what you noticed: the yellow damper refills easily when you manually pull ink, but the printer won't sustain yellow ink delivery during printing or cleaning. That pattern usually means the ink path is not fully blocked, and the problem is more likely one of these:

• a seal/vacuum problem at the damper-to-head connection

• a cap station / pump not producing enough suction

• air intrusion (micro-leak) that breaks the siphon under normal operation

• a printhead nozzle plate clog that resists regular cleaning even though the damper can be filled

Here's what to check next, in the most practical order.

1) Confirm the yellow damper gasket is sealing tightly to the printhead

On EcoTank models, ink delivery depends heavily on maintaining a stable seal. If the damper gasket is slightly hardened, warped, nicked, or not seated perfectly, it can break the vacuum/siphon effect. You can still fill the damper by syringe (because you are providing suction), but the printer won't be able to pull ink consistently during printing.

What to do:

• Remove the yellow damper again and inspect the gasket/sealing surface.

• Look for flattening, cracks, swelling, or ink crust.

• Reinstall carefully and ensure it sits straight-no tilt, no gap.

• If the damper is old, stiff, or deformed, replacement is often the fastest fix.

Why this fits your symptoms: a damper can look "fine" yet still leak air at the seal. Even a tiny leak can stop ink delivery under normal operation.

2) Check whether the cap station is making proper contact on the yellow side

Cleaning cycles only work if the cap station seals against the printhead and the system can build suction. If the cap top is worn, misaligned, or contaminated, cleaning won't pull ink through the yellow channel-so the damper stays empty during normal operation even though the line itself isn't clogged.

What to do:

• Inspect the cap top for ink crust, dents, tears, or a "collapsed" sponge/rubber edge.

• Check for uneven contact: sometimes one side caps well while the other doesn't.

• If the printer has been used heavily, the cap can wear out and lose its ability to seal.

Quick symptom check: If cleaning never changes anything and the damper keeps ending up empty, it strongly suggests the cleaning system is not creating suction.

3) Verify the waste pump and waste tubing are actually pulling suction

On many Epson designs, the pump pulls ink during cleanings through the cap station into the waste path. If the pump is weak, the waste tube is pinched, or the waste path is partially clogged, suction drops and ink can't be drawn through the head.

What to check:

• Look for kinks, pinches, or dried ink buildup in waste lines.

• Check the waste pad/box area for abnormal blockage or backing up.

• Listen during cleaning: a pump can "sound like it runs" but still be too weak to pull properly.

Why it matters: even if the ink supply line is clear, the printer still needs the pump/cap system to maintain the pressure balance that supports ink delivery.

4) Inspect the yellow ink tube and fittings for micro air leaks

You already proved ink can flow, but air intrusion can still break the system under normal printing. A tiny leak in the yellow line, a loose fitting, or a hairline crack can allow air to enter. When that happens:

• the damper may refill during manual suction,

• but during printing the flow collapses because the line draws air instead of ink.

What to do:

• Inspect the yellow tube for whitening, stiffness, cracks, or wet ink staining.

• Check connection points for looseness.

• Watch for bubbles in the line (if visible). "Champagne bubbles" are a red flag.

5) Don't rule out a stubborn yellow nozzle plate clog (even if ink refills manually)

It's possible for the damper to be full and the line clear, but the nozzles themselves are blocked-especially if the printer sat for a short time, got exposed to dry air, or printed certain types of content. In that case, standard cleanings may not be enough.

Clues that point to nozzle blockage:

• You can verify ink is present at the damper/head, yet the nozzle check shows zero yellow.

• Cleanings do nothing and the pattern doesn't improve at all.

This is where deeper cleaning methods or parts related to capping/cleaning performance become relevant-because the printer's built-in cleaning depends on a strong seal and suction.

What parts are most commonly needed for this exact symptom

Since you asked what you might need to buy, here are the usual "most likely" part categories for your specific situation (manual refill works, printing doesn't):

• Yellow damper (or damper set) if the gasket is leaking or the internal check behavior is inconsistent

• Cap station / cap top if the cap isn't sealing or is worn

• Pump / maintenance station components if suction is weak

• Ink tubing segments/fittings if there's air intrusion

The best "next part" depends on what you find in steps 1-4. In many cases, the damper seal and the cap station seal are the make-or-break items.

Error codes

You didn't mention any printer error codes in your message. If you're seeing a specific code on the printer display or in the driver (even intermittently), that would be important to factor in-please note it exactly as shown, because certain codes can point more directly to maintenance station, carriage, or sensor issues.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems, and the same symptom can come from multiple mechanical causes. Because of that, we're not able to provide remote troubleshooting, suggestions, or support for printer repairs. We do offer an in-person evaluation and repair service through our local diagnostic facility: printer repair service (https://bchtechnologies.com/printer-repair-service). Due to high demand, we operate on a first-come, first-served basis, and it may take a few weeks before we can accept your printer for drop-off. Our services are structured to repair either the entire printer or specific parts, with clear instructions on how to proceed. That said, we recognize our rates aren't the most economical, so we strongly encourage self-help through online research. You can start on YouTube or by visiting our channel homepage: BCH Technologies on YouTube (https://youtube.com/@bchtechnologies). To find the most relevant content, use the search icon next to "About" on the right-hand side of the menu bar. I receive dozens of questions every day asking about videos on specific topics, and after creating videos for over nine years, it's difficult to remember every single one-so YouTube's search tool is the fastest route. It can also recommend relevant videos from other channels that may help with your exact symptoms.

Thanks again for your support and for taking the time to write such a clear, detailed description-those observations are exactly what helps narrow down the real cause quickly.