How to Install Dampers on the Epson ET-8550 and Locate the Correct FFC Cable for the ET-4700 (Troubleshooting Guide)

Customer Question

I'm working on installing dampers on my Epson ET-8550. I also need help finding the motherboard and the FFC cable that connects the main board to the screen board on an Epson ET-4700. I referenced your video but wasn't sure where to locate the correct parts.

Answer

Understanding What You Need: ET-8550 Dampers and ET-4700 FFC Cable

You've asked about two separate models, and each has its own repair considerations:

1. Installing Dampers on the Epson ET-8550

The Epson ET-8550 is a six-color EcoTank printer, and when modifying it-such as converting for DTF, pigment, or sublimation printing-dampers (also known as ink filters or ink buffers) are often added to help regulate ink flow and reduce the risk of nozzle dropouts.

Key points to keep in mind:

• The ET-8550 does not come with dampers from the factory.
  Like most EcoTank models, ink flows from the tanks through tubes straight into the printhead.

• Adding third-party dampers requires:

  • Opening the printer

  • Accessing the ink lines

  • Cutting and inserting each line between the tank assembly and the printhead entry point

• Dampers can help stabilize ink flow, but improper installation can cause:

  • Air bubbles

  • Tube kinks

  • Ink starvation

  • Printhead over-pressurization

• Epson does not support damper installation, so the modification must be done carefully and at your own discretion.

If you're following our conversion or repair videos, be sure to take your time with the tubing paths. Avoid sharp bends, and ensure each damper is seated securely without air leaks.

2. Finding the Motherboard and FFC Cable for the Epson ET-4700

You also asked about the FFC cable (Flat Flexible Cable) that connects the ET-4700's main motherboard to the front control panel screen board.

This cable is often referred to as the Control Panel FFC or Display Board Ribbon Cable.

If you need this part, the easiest way is to search for:
"control panel FFC" on the BCH Technologies store:
Control Panel FFC Cable - BCH Technologies (https://bchtechnologies.com)

The cable you're looking for is typically:

• A narrow, multi-pin ribbon

• Used for data and power transfer between the mainboard and the LCD button board

• Model-specific-FFC cables vary in length, pin count, and orientation

Because of this, make sure you match:

• Pin count

• Length

• Connector direction (A-type/B-type)

• Model compatibility

If the entire ET-4700 motherboard or screen board also needs replacing, those parts can sometimes be salvaged from donor machines. EcoTank boards are coded to the printer's serial configuration, so replacing the board with an exact match is ideal.

Important Note on Error Codes (If Applicable)

Although you didn't list error codes in this case, FFC cable issues commonly trigger:

• "Communication Error"

• "Scanner Error"

• "Control Panel Error"

• LCD freezing or not powering on

If any of these occur, the FFC cable is a strong suspect.

A Friendly Reminder About Repair Support

Printer repair can be very hands-on and detail-sensitive, and because of this, we're unable to provide step-by-step remote troubleshooting or repair instructions. However, if you need in-person help, we offer diagnostics and repair through our local service center:
BCH Printer Repair Service (https://bchtechnologies.com/printer-repair-service)

We operate on a first-come, first-served basis, and due to high demand, wait times may be a few weeks. Our repair options include full-printer service or individual component repair, depending on what you need.

If professional repair isn't the most economical choice for you, we strongly recommend exploring online resources. Start by using the search icon on the BCH Technologies YouTube channel homepage (https://youtube.com/@bchtechnologies). With nine years of uploaded videos, even I can't always remember every topic covered, but YouTube's search feature will quickly pull up related videos-including helpful content from other creators.

Thank you again for contacting us and for supporting our work. We appreciate your patience and your involvement in the BCH community. If you have more questions or need clarification, feel free to send them anytime.