Epson ET-8550 Printhead Crash and Capping Station Stuck - Causes and Fixes

Question:
I recently purchased and replaced the printhead and FFC cables on my Epson ET-8550. After reassembly, the printhead kept crashing to the left side, but I managed to solve that issue. Now, the capping station has popped up and will not go back down. Why did this happen, and how can I fix it?

Answer:

1. Printhead Crashing to the Left

• When a newly replaced printhead crashes to the left side, the cause is usually either:

  • Mis-seated or damaged FFC cables connecting the head to the mainboard.

  • A problem with the encoder strip (the thin clear strip that guides printhead positioning). If the strip is dirty, loose, or misaligned, the printhead sensor cannot read it correctly and slams into the side.

• Once this is corrected, the printer can resume normal movement.

2. Why the Capping Station Popped Up and Won't Retract

• The capping station is part of the maintenance unit that seals and cleans the printhead. It is normally raised and lowered by a gear-driven cam mechanism connected to the service motor.

• If it popped up and won't go back down, common causes include:

  • The service motor timing was thrown off during reassembly.

  • The gears in the maintenance unit slipped out of alignment when the printhead was crashing.

  • A blockage (like dried ink or a jammed spring) is preventing the station from lowering.

3. How to Fix It

• Check Gear Alignment: Remove the maintenance unit and inspect the gear system. If the capping pad is stuck in the raised position, rotate the gear manually to reset it to the lowered position.

• Inspect the Service Motor: Ensure the motor is driving the gear train correctly and that the timing isn't offset. Sometimes disconnecting and reconnecting the motor gear resets it.

• Clean and Lubricate: Excess dried ink around the capping station can cause the mechanism to seize. Clean the rails and pivot points with isopropyl alcohol and apply a light, silicone-based lubricant if needed.

• Recheck Reassembly: Since you replaced both the printhead and FFC cables, double-check that no cables or parts are obstructing the maintenance unit's normal movement.

4. Why It Happened

• The printhead crash may have caused the service motor to skip timing or forced the capping station mechanism out of sync. Once that happens, the capping station can remain locked in the raised position, preventing normal operation.

Addressing printer problems like this can be complicated because they require hands-on inspection and mechanical adjustments. For this reason, we cannot provide remote troubleshooting or direct repair support. However, we do offer an in-person evaluation and repair service (https://bchtechnologies.com/printer-repair-service). This service operates on a first-come, first-served basis, and due to demand, it may take several weeks before we can process your printer. We repair both full printers and individual components, but we recognize that our pricing may not always be the most economical. Many customers prefer to begin with self-research, and a great resource is our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon next to the "About" tab to look for videos on Epson maintenance units, encoder strip troubleshooting, and ET-8550 repairs.

Thank you again for reaching out and for supporting BCH Technologies. Your engagement helps us continue building resources that serve the wider printing community.