Epson EcoTank ET-8500 Error 000031 and Screeching on Startup: Causes and Fixes

Question:
I have a converted Epson EcoTank ET-8500 printer. When it starts up, the printhead moves to the left side and makes a screeching noise. It stops at the far left, and although I can move the carriage manually by hand, it still refuses to print. What could be causing this?

Answer:

Regarding your Epson EcoTank ET-8500 that moves left and screeches during startup, this behavior is commonly associated with Error Code 000031, and it's typically related to an encoder or carriage alignment issue.

Here's a detailed breakdown of what's happening and how to fix it:

1. Dislodged Carriage Encoder Strip (Timing Belt / CR Scale)

The most common cause is that you've accidentally pulled the transparent encoder strip (also known as the timing belt or CR scale) out of the carriage sensor during maintenance or cleaning. This clear plastic strip runs horizontally behind the carriage and helps the printer determine the exact position of the printhead.

When the encoder strip is out of its sensor track, the printer can no longer detect the carriage's position. As a result, the printer keeps driving the printhead left until it hits the side wall-causing the screeching noise you hear.

To fix this:

• Power off the printer and unplug it.

• Open the top cover and locate the clear strip running behind the carriage.

• Look closely at the small black optical sensor on the back of the carriage assembly. The encoder strip should pass directly through that sensor.

• If the strip is hanging loose, carefully thread it back through the slot in the sensor.

• Ensure it's not twisted or smudged. Clean it gently with a lint-free cloth and isopropyl alcohol if necessary.

2. Carriage Jam or Blocked Rail

If the encoder strip is properly seated, check that the carriage rail is clean and free of obstructions. Dried ink, spilled cleaning fluid, or debris can cause resistance that mimics a jam. Apply a small amount of lubricant (such as PTFE grease) to the metal rod where the carriage slides.

3. Paper Feed Sensor or Encoder Disc Issue

Although less common, if the screeching occurs before the carriage moves, the paper feed motor or encoder disc at the end of the roller shaft may be dirty or slipping. Cleaning these components can restore proper motion sensing and stop the noise.

4. Firmware Lock After Error 000031

If the printer previously displayed Error 000031, it might still be in protection mode. After reseating the encoder strip, unplug the power for 5 minutes, then restart the printer. In some cases, performing a hard reset (holding the power and reset buttons simultaneously for several seconds) can clear residual memory errors.

If you've converted your ET-8500 for DTF printing, remember that extra ink residue or film powder can sometimes interfere with sensors, so keeping those parts clean is essential.

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. Therefore, we're unable to provide remote troubleshooting, suggestions, or direct repair support. We do offer in-person diagnostic and repair services through our local printer repair facility (https://bchtechnologies.com/printer-repair-service). Due to high demand, we operate on a first-come, first-served basis, and it may take a few weeks before we can evaluate your printer. Our repair services cover both full printer repairs and individual part replacements, with clear instructions on how to proceed.

That said, if you prefer DIY troubleshooting, we highly recommend checking out our YouTube channel (https://youtube.com/@bchtechnologies). Use the search icon beside "About" on the menu bar to look for videos related to Error 000031 or Epson EcoTank carriage repair. Over the years, we've created hundreds of tutorials, and searching directly will help you find the most relevant video quickly.

Thank you again for reaching out and for your continued support of BCH Technologies. We truly appreciate your dedication to learning and maintaining your printer, and we're always inspired by the passion of our community members who take the initiative to solve technical challenges like this one.