How to Troubleshoot Epson Error 031004 (Paper Jam) Caused by Printhead or Mainboard Failure

Question: My brand-new printer is showing error 031004 "paper jam," but there is no actual jam. I accidentally dented the printhead, and I'm wondering whether that damage could be the cause. Can you confirm if the dent is responsible for this error?

Answer:

Why Error 031004 Appears Even Without a Paper Jam

Despite the wording, Error 031004 ("Paper Jam") is often unrelated to actual paper movement in certain Epson-based printers. Instead, it can be triggered by failures in the printhead, FFC cable, or mainboard, all of which are critical components in the printer's startup safety check.

1. Printhead Thermistor Failure (Most Common Cause)

The printer contains a thermistor inside the printhead. This component measures temperature by detecting voltage changes. When the printer powers on, it sends a diagnostic electrical pulse to the thermistor.

If the thermistor reports:

• Voltage outside expected range, or

• A reading that suggests excessive heat,

the printer assumes that the printhead is overheating or shorted.

Since firmware is programmed to shut down for safety, it triggers a misleading error such as a paper jam-even when everything is clear.

A dented or physically damaged printhead, as you mentioned, can absolutely cause this type of thermistor failure. Even a small dent can:

• Damage the internal layers

• Short two circuits

• Break the thermal sensor

• Cause incorrect or unstable resistance readings

All of these conditions can trigger Error 031004.

2. Verifying Printhead Health With a Multimeter

To determine if the printhead is truly the cause, you can perform a continuity and resistance check.

We provide a detailed step-by-step guide and datasheet here:
Printhead Multimeter Testing Sheet
(https://bchtechnologies.com/products/instruction-sheet-for-l1800-1390-printhead-testing-with-multimeter-digital-download-instant-download-delivered-to-your-email-copy?_pos=3&_sid=792afc802&_ss=r)

This includes:

• Pin definitions

• Expected resistance values

• Short-circuit detection

• Video instructions

If the multimeter shows irregular readings, shorts, or open lines, the printhead is confirmed faulty.

3. Other Possible Causes if the Printhead Tests OK

If the printhead passes the multimeter test, then the source of Error 031004 is likely elsewhere:

A. Damaged FFC Cable (Flat Flexible Cable)

A shorted or cracked FFC cable can:

• Send false signals

• Interfere with thermistor readings

• Trigger startup safety errors

Check for:

• Burn marks

• Bent traces

• Exposed copper

• Tears or folds

• Loose seating at either connector

B. Burnt or Failing Mainboard

If the printhead and cable are both healthy, the mainboard may be at fault.

Mainboard failures occur due to:

• Overcurrent from a damaged printhead

• Ink contamination

• ESD damage

• Voltage spikes

We do offer mainboard repair services if your printhead is confirmed to be functioning properly.

Addressing printer problems can be a complicated process because of how hands-on and sensitive the components are. For this reason, we're not able to provide remote troubleshooting or guided repair instructions. However, we do offer in-person evaluations at our BCH Technologies Printer Repair Service (https://bchtechnologies.com/printer-repair-service). Due to demand, our process is first-come, first-served, and it may take a few weeks before we can receive the printer. We repair entire printers or individual components, with clear instructions provided. We also acknowledge that our prices may not be the most economical. For this reason, we often recommend starting with self-help via online research, including YouTube or our own BCH Technologies YouTube channel (https://youtube.com/@bchtechnologies). You can use the search icon on the channel's main page to find specific topics. After producing videos for nine years, it's impossible to remember them all, and YouTube's search suggestions can guide you to related videos from other creators as well.

Thank you again for reaching out. We appreciate your patience, your engagement, and your support. If you have any further questions, feel free to contact us anytime.