Epson ET-8550 Won't Power On After Installing CISS System

Question:
I installed a Continuous Ink Supply System (CISS) on my Epson ET-8550. After turning the printer on, the printhead moved but then I heard a screeching sound. I unplugged the printer to fix the printhead lock because it wouldn't allow the carriage to move all the way to the left. After plugging the printer back in, it now won't power on. What should I do?

Answer:

What Happened with the Screeching Noise

The screeching sound you heard typically comes from the carriage motor or drive belt when the printhead is obstructed. In your case, the carriage lock may not have been fully released before the printer powered on. When the printhead tried to move against that resistance, the motor strained, which can trigger mechanical stress or even damage the belt/clip assembly.

Why the Printer Won't Power Back On

There are a few possible causes for the printer not turning back on after this event:

1. Internal Fuse or Power Supply Failure

   • Printers like the ET-8550 have protective fuses inside the power board. If the motor experienced too much stress, it can cause an electrical surge that blows a fuse, cutting power to the whole unit.

   • In some cases, the power supply itself may have been damaged and needs replacement.

2. Mainboard Protection Triggered

   • If the main logic board sensed a fault, the printer may refuse to power on until the issue is reset. Unfortunately, Epson doesn't provide an easy reset method for end users in this situation.

3. Carriage Lock or Jam Still Present

   • If the lock was only partially released or if something is still obstructing the carriage, powering the printer back on may be unsafe, and the unit may not complete startup.

What You Can Check

• Verify the Lock is Fully Released: Make sure the printhead carriage moves freely left to right without resistance before powering on again.

• Inspect for Loose or Damaged Cables: During installation of a CISS, cables sometimes get pinched in the carriage path or dislodge connections inside the printer.

• Test the Power Source: Confirm the outlet and cord are working, though in this case it's unlikely the simple issue of power supply.

Likely Repair Path

Unfortunately, when an Epson ET-8550 won't power on after a carriage jam, it usually points to a blown internal fuse on the power board or a damaged power supply. Repair would require:

• Opening the printer and testing continuity on the power board.

• Replacing the fuse, power supply unit, or-if more severe-the mainboard.

This is not something Epson authorizes as a user repair, and it does require a technician with the right tools and parts.

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) at our local diagnostic facility. Because of high demand, repairs are handled on a first-come, first-served basis, which may mean waiting a few weeks before your printer can be dropped off and evaluated. Our services cover full-unit repairs as well as specific part replacements, but we also recognize that our rates may not be the most budget-friendly. For many users, self-help remains the most practical option. We recommend searching for solutions on YouTube, starting with our BCH Technologies channel (https://youtube.com/@bchtechnologies). Use the search function on our channel's menu bar to find videos on topics like carriage jams, power issues, or EcoTank maintenance. With more than nine years of content, this is the fastest way to locate relevant tutorials, and YouTube may also suggest other helpful resources.

Thank you again for reaching out. We greatly appreciate your patience and support, and we'll continue to provide the best resources possible to help you resolve printer problems.