Diagnosing Power-On Failures and Dual-Red-Light Errors on a Procolored F13 / Epson L1800-Based DTF Printer

Question: What causes a Procolored F13 L1800 DTF printer to power on with solid red ink and paper lights, no front power button response, intermittent clicking, and mixed green-light indicators on the internal boards-despite installing a repaired motherboard, a new printhead, new waste station, new dampers, and rewired cables?

A customer reported that after extensively refurbishing an F13/L1800 DTF printer-including a repaired motherboard, new printhead, new waste station, new dampers, and new head cables-the machine still refused to start properly. The rear power switch activated the power supply and circulation pump, but the front power button never lit up. Instead, both the paper and ink LEDs stayed solid red. Several internal boards displayed flashing or solid green LEDs, the power supply showed two solid green lights, and the printer occasionally made clicking sounds but did not move the carriage. Voltage readings from the three-wire power harness measured approximately 42.82V, 0V, and 42.24V, even though the power supply label indicates outputs for 24V, 42V, and 3.3V. All fuses and MOSFETs tested good. The customer asked whether this issue had been seen before and what steps could help diagnose it.

Based on the symptoms you described, your printer is definitely reporting an internal error, and the two solid red lights are the most important clue. This dual-LED state is an Epson error indicator, even on converted DTF machines, and it is consistent with the printer detecting a fault before the carriage can initialize.

Below is a detailed breakdown of how to interpret the issue and the next steps to take.

1. What the solid red ink + red paper lights mean

When both lights stay solid red at startup, the printer is refusing to complete its power-on sequence. This behavior is consistent across the L1800 family.

Typical causes include:

• CR encoder (APG) sensor errors

• Carriage motor stalls

• Paper sensor or PF motor errors

• Printhead short-circuit detection

• Mainboard firmware panic halt

The exact error code is not displayed on the panel-you need software to read it.

2. Why the internal board lights matter

You mentioned:

• Two small boards have flashing green LEDs

• Another board has two solid green LEDs

• The power supply shows two solid green LEDs

These LEDs only indicate that the boards are receiving power. They do not diagnose functional issues and do not rule out an error on the mainboard, sensors, or head driver.

It does confirm, however, that:

• Your PSU is delivering power

• The 42V line is good

• The standby voltage line is good

• The motherboard is booting far enough to signal an error

That rules out the most catastrophic power failures.

3. Your voltage readings are normal for this type of supply

Your JLNKE switching PSU lists three outputs:

• A - 24V

• B - 42V

• C - 3.3V

But you read:

• 42.82V

• 0V

• 42.24V

This is actually consistent with many DTF-mod PSUs where:

• The 3.3V line is not always present on machines using adapted L1800 controllers

• The 24V rail is sometimes bridged internally to 42V for DTF circulation mods

• The center pin can be ground or floating depending on board configuration

Since your LEDs turn on and the mainboard boots enough to throw an error, your PSU is functioning.

4. The crucial next step: Retrieve the Epson error code

This is the most important part of diagnosing your issue.

You need to use the Epson Adjustment Program (also known as the Service Tool) to read the internal error log.

How to check the error code:

1. Open the Adjustment Program on your computer.

2. Select the USB port associated with the printer.

3. Click Particular Adjustment Mode.

4. Scroll to Printer Information Check.

5. Click Check.

6. The top line will show the printer's most recent error code-Error No. 1.

Interpreting Epson's secret error codes

Search:
"BCH Epson Error" on Google
This brings up our guide to Epson's internal/hidden "Triple Secret Error Codes" that are not displayed on the panel.

Possible codes may include:

• 031002 (APG sensor error)

• 031006 (Carriage home position failure)

• 031005 (PF motor load detected)

• 031004 (Printhead temperature error)

• 031007 (Head driver overcurrent)

These codes show exactly what subsystem is preventing startup.

Video walkthrough

We also made a quick video showing how to read the code:
How to Check Epson Error Codes - https://youtube.com/shorts/FPZzpyYuZLE

Once you retrieve the code, you'll know which component is triggering the shutdown-much more reliable than guessing.

5. Additional insight on your symptoms

• The fact that the white ink circulation pump runs indicates 42V is present.

• The front power button staying dark while red LEDs appear is typical of error-halt mode.

• The intermittent clicking is usually the carriage motor attempting (and failing) to initialize.

• Because you replaced the printhead and cables, if the error relates to:

  • 031007 (Head driver overcurrent)

  • 031004 (Printhead thermal error)
    ...then the new printhead or cables may still be at issue.

But again, the Adjustment Program will tell you precisely.

Important Note About Printer Repair Services

Printer repair is inherently hands-on and often requires physical testing. Because of this, we're unable to provide remote diagnostics or step-by-step repair support. However, BCH Technologies does offer in-person evaluation at our local diagnostic facility (Printer Repair Service - https://bchtechnologies.com/printer-repair-service). Due to high demand, intake typically operates on a first-come, first-served basis, and there may be a waiting period before we can process your printer.

Our service options cover both full-printer repairs and component-level work, with clear guidance on next steps. That said, our rates may not always be the lowest, so we strongly encourage self-research whenever possible. You can find extensive troubleshooting resources by searching YouTube or visiting our channel directly (BCH Technologies on YouTube - https://youtube.com/@bchtechnologies). Use the search icon on the channel page to locate specific topics-after nine years of creating repair videos, even we can't remember every one by memory! YouTube may also recommend helpful videos from other creators.

Thank you again for contacting us and for your patience. We truly appreciate your support and trust. If you're able to retrieve the exact error code using the Adjustment Program, feel free to share it-we'll gladly help interpret what it means.