Why Your Epson ET-8550 Isn't Pulling Ink Into the Waste Tank

Question: Why is my Epson ET-8550 not pulling any ink into the waste tank during printhead cleaning or power cleaning, and how does the white switch behind the printhead affect the waste pump? I also noticed a piece of plastic blocking the switch from moving-could this be the cause?

You explained that your ET-8550 is not dropping ink levels, no ink reaches the waste tank during cleanings, and you suspect the white switch behind the printhead may be involved. You also mentioned performing a shoeshine cleaning earlier, and that a piece of plastic seems to be preventing the switch from moving. You want to understand whether this is the cause and how to diagnose the issue.

Answer:

Possible Reasons No Ink Is Reaching Your Waste Tank

When a printhead cleaning or power cleaning produces no ink movement and no change in ink levels, one of two systems is malfunctioning:

1. The suction path (capping station → waste tube → waste pump) is blocked or not sealing.

2. The mechanical linkage that raises/lowers the capping station-controlled by the white switch-has become misaligned.

Your observation about the white switch and the piece of plastic blocking it is a very important clue.

1. Check Whether the Capping Station Is Clogged

Move the printhead off the capping station so you can access the waste tube.
Then:

• Use a syringe to gently pull suction from the waste tube.

• If you can't pull any ink or fluid, the waste path (pump or tube) may be clogged.

• If suction is difficult but possible, the capping station pad may be blocked by dried ink.

This is the first diagnostic step because if the waste path is blocked, the cleaning cycles will fail immediately.

2. Test Whether the Printhead Can Seal Properly

Next, allow the printhead to park over the capping station and repeat the suction test:

• If you pull strong vacuum:
  The printhead nozzles themselves may be clogged, preventing ink from flowing. This can happen after a shoeshine cleaning if drying occurs at the nozzles.

• If you only pull air (no seal):
  The capping station is not rising high enough to contact the printhead bottom.
  This is where the white switch and the plastic interference come in.

3. The White Switch and the Mysterious Plastic Blocker

Epson printers use a mechanical linkage system that:

• Moves the capping station up and down

• Controls the waste pump engagement

• Sets the gear selection for maintenance modes

The white switch you're referring to acts like a gear selector for the printer's maintenance cycle.
If a plastic tab is sticking through and preventing the switch from moving, then:

• The capping station cannot raise

• The printhead cannot seal

• The waste pump cannot engage

• No suction is generated during cleaning

• Therefore, no ink reaches the waste tank

This matches your symptoms exactly.

This piece of plastic is normally part of the printer's gear train that drives the capping station. If it slips out of position-sometimes after a shoeshine cleaning or from a manual movement-it disrupts the entire cleaning system.

4. APG Height and Capping Station Alignment

Even if the capping station isn't visibly damaged, its alignment and height (APG height) matter.

If the station sits too low:

• It won't seal the printhead.

• Cleaning cycles pull air instead of ink.

• Ink levels don't drop, and the waste tank stays dry.

Adjusting the APG height and ensuring proper front-to-back seating of the capping station may restore normal operation.

Summary of the Most Likely Issue

Based on everything you described, the most likely cause is:

The plastic tab preventing the white switch from moving has knocked the capping station linkage out of position, so it no longer rises to seal against the printhead.

This prevents all suction, causing zero ink movement during any cleaning cycle.

Important Note About Repair Support

Dealing with mechanical alignment issues, linkage timing, and capping-station height adjustments is highly hands-on. Because of that, we aren't able to guide remote repairs or provide step-by-step mechanical corrections. We do offer an in-person evaluation and repair service through our local diagnostic facility (Printer Repair Service - https://bchtechnologies.com/printer-repair-service). Please note that due to high demand, repairs are handled on a first-come, first-served basis, and turnaround may take a few weeks depending on the queue.

Our services include full printer repairs or part-specific servicing, but we understand that our pricing may not fit every budget. For this reason, we encourage users to explore self-help options through YouTube. You can start by using the search tool on the right side of the menu bar of our YouTube channel homepage (BCH Technologies Channel - https://youtube.com/@bchtechnologies). With over nine years of content, we receive many requests about specific topics, and searching directly is the fastest way to locate related videos. YouTube may also recommend additional videos from other creators that could help.

Thank you again for taking the time to reach out and for supporting BCH Technologies. Your engagement means a great deal to us, and we hope this detailed explanation helps you move forward with diagnosing the issue. If you ever need further clarification, feel free to contact us anytime.