Epson ET-8550 Error Code 031006 After Screw Dropped Inside - Causes and Fixes

Question:
I have an Epson ET-8550 printer that is showing error code 031006. I accidentally dropped a screw inside the printer and shook it to the left to get it out. I then opened the printer on the left side and retrieved the screw. However, the error code still appears. I replaced one of the ink tubes by taking the printer apart and reassembling it, and I also cleaned the printhead. The printer powers on, but after about three seconds, the error reappears. I watched some of your videos and think the issue may be with the motherboard. Is it possible to send the printer to you for repair?

Answer:

Regarding your Epson ET-8550 issue, the error code 031006 typically indicates a fatal hardware error. This error is usually triggered when the printer detects an internal mechanical or electrical fault during startup. Since you mentioned that a screw had fallen inside and you had to disassemble the unit, there are a few possible causes:

1. Loose or Misaligned Cables

   • The ET-8550 has ribbon cables and sensor connectors that are extremely sensitive. Even a slightly loose connection to the CR encoder sensor, mainboard ribbon cable, or ink supply tubing sensors can trigger 031006. Double-check that every cable is seated firmly, especially those running from the carriage unit and printhead to the motherboard.

2. Printhead or Carriage Issues

   • Cleaning the printhead is fine, but if the head was removed or reinserted, the alignment pins or electrical contacts could have shifted. Any misalignment can cause the printer to start up but then fail almost immediately, as you described.

3. Motherboard (Main Board) Damage

   • Unfortunately, shaking the printer or having a loose screw inside may have caused a short circuit on the motherboard. This is consistent with your suspicion, especially since the error occurs only a few seconds after power-up, suggesting that the board passes an initial check but fails during system initialization.

4. Residual Mechanical Obstruction

   • Even though you removed the screw, small fragments of metal or displaced plastic pieces may still be inside, interfering with sensors or carriage travel.

5. Tube Replacement Factor

   • When ink tubes are replaced, the air pressure balance inside the ink delivery system can be disrupted. If the system detects improper pressure or tubing connection, it may halt with this error.

What you can do before sending it in:

• Carefully reseat all ribbon cables, particularly the wide FFC cables to the printhead and motherboard.

• Inspect the mainboard visually with good lighting to see if there are burn marks or scratches from the dropped screw.

• Check the encoder strip and sensor on the carriage; if dirty or scratched, it can throw a hardware error.

If after these checks the error persists, then your diagnosis of a motherboard issue is likely correct.

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 via our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis, which means it might take a few weeks before your printer can be assessed after drop-off. Our services are structured to repair either a whole printer or specific parts, with clear instructions on how to proceed. However, we acknowledge that our rates aren't the lowest available. For that reason, we also highly recommend self-help options such as researching through YouTube. On our YouTube homepage (https://youtube.com/@bchtechnologies), you can use the search icon next to "About" to find relevant videos. Since I've published hundreds of videos over nine years, it's impossible to recall each one, so using search is the fastest way to locate the right resource. Plus, YouTube may suggest videos from other channels that can also help.

Once again, thank you for your patience and for contacting us. We truly appreciate your support and wish you the best in getting your ET-8550 back up and running.