Epson ET-8550 DTF Conversion: How to Fix Error Code 031004 After PCP Board Installation

Question:

After following the ET-8550 DTF conversion process (including upgrading the printhead with nipples to improve white ink flow), a customer reports that the printer throws error code 031004 about 10 seconds after startup. They're wondering if the PCP board was installed the wrong way, or if the issue was caused by accidentally touching the PCP board (a smudge/fingerprint), which they later cleaned off. They want to know whether they should reassemble it and try again.

Related video link: [YouTube comment thread] (https://www.youtube.com/watch?v=EAGy6vtVtEQ&lc=Ugy-YE0EVeKrhqazySR4AaABAg)

Answer:

Now, about error code 031004 appearing about 10 seconds after startup: in most cases, 031004 is associated with the printer detecting that the printhead is "too cold" or not warming/reading temperature correctly. In practical repair terms, this usually doesn't mean the room is cold-it means the printer is not getting the correct signal from the printhead's temperature/thermal circuit, so it interprets it as an abnormal temperature condition.

That's why this error often shows up after a conversion or hardware work: it's commonly triggered by connection, seating, or signal integrity issues rather than a "dirty board" problem.

Why 031004 Happens Right After Power-On (Most Common Causes)

1) Printhead cables not fully seated or slightly misaligned

Your note ("10 seconds after it starts up") fits perfectly with a connection check occurring during initialization. If the printer can't properly read the printhead's temperature circuit through the cable, it may throw 031004 quickly.

What typically causes it:

• Cable not inserted straight (even slightly off can matter)

• Latch not fully locked

• Cable not pushed all the way into the connector

• Cable creased, pinched, or stressed during reassembly

Key point: This is the most common reason we see when 031004 happens right after a printhead-related modification.

2) Printhead not installed or seated correctly

If the printhead isn't sitting flat, or the mounting pressure is uneven, the cable can "look" connected but not actually make reliable contact. During conversions-especially when adding nipples and reworking tubing-there's often extra tension that can twist the head position slightly.

Things that can contribute:

• Mounting screws not snugged evenly

• Head slightly lifted on one side

• Routing/tube tension pulling on the assembly

3) PCP board installed incorrectly (possible, but usually more dramatic symptoms)

You asked whether the PCP board was installed the wrong way. It can happen, but typically when a board is reversed or a connector is forced, the results are usually:

• Printer won't initialize properly at all

• Multiple error codes

• No response / immediate shutdown behavior

If your printer starts and then errors after ~10 seconds, it still points more strongly toward a printhead temperature read issue (cable/head connection), not a simple "board touched" issue.

That said, the PCP board and cable paths can indirectly matter if something about the board installation caused a cable to be:

• pinched by a cover,

• slightly unplugged,

• or routed under tension.

4) Fingerprint/smudge on the PCP board (less likely unless it caused contamination or static damage)

A light smudge is usually not enough to cause a hard error like 031004, especially after you cleaned it. Fingerprints can be an issue when:

• they trap conductive debris,

• moisture + residue creates leakage paths,

• or there was a static discharge event (ESD) while handling.

But in most real-world cases, a smudge alone is not the reason for 031004. The printer is usually complaining because it can't properly read or validate the printhead temperature circuit.

What You Can Do Before Reassembling Everything Again (Practical, Low-Risk Checks)

• Reseat the printhead cable(s): remove and reinsert carefully, perfectly straight, and lock the latch fully.

• Inspect the cable ends: look for bent crease marks, torn traces, or contamination at the contact edge.

• Verify the printhead is mounted correctly: flat seating, even screw pressure, nothing pulling sideways.

• Check cable routing: make sure nothing is pinching the cable when covers go back on.

• Double-check all connectors you touched during the PCP board install: sometimes one "almost plugged in" connector is all it takes.

If everything looks solid and properly seated, then yes-put it back together and test again. In many cases, a careful reseat fixes it.

Important note about the error code

Since you specifically mentioned it: Error code 031004 is commonly tied to a printhead temperature/thermal read issue, often described as the printhead being "too cold." In practice, that usually means connection/security of the printhead cable or printhead seating/installation needs to be revisited.

Addressing printer issues can be complicated because the problems are hands-on and component-specific, and that limits what we can reliably diagnose remotely. For that reason, we're not able to provide remote troubleshooting, step-by-step repair instructions, or direct support for printer repairs. We do offer an in-person evaluation and repair option through our local diagnostic facility: [BCH Technologies Printer Repair Service] (https://bchtechnologies.com/printer-repair-service). Because demand is high, we work on a first-come, first-served basis, and it may take a few weeks before we can accept a drop-off. Our service structure supports either full-printer repairs or specific part-focused repairs with clear intake steps. That said, we recognize our rates may not be the cheapest option, so we strongly encourage self-research first. A great starting point is YouTube-especially our channel homepage: [BCH Technologies YouTube Channel] (https://youtube.com/@bchtechnologies). Use the search icon near the "About" section on the right side of the menu to quickly locate relevant videos. I receive many daily requests asking which video covers a specific issue, and after nearly a decade of publishing content, it's tough to remember every topic by memory-YouTube's search is the fastest route, and it may also suggest helpful videos from other creators.

Thanks again for reaching out and for supporting our work-especially on YouTube. We truly appreciate it, and I hope this helps you get back up and running as smoothly as possible.