Epson L18050 DTF Showing Paper Jam and Blinking Lights? ET-8550 PE Sensor & Carriage Troubleshooting Guide

Question

My Epson L18050 was converted to DTF. It is now showing a paper jam error and all the lights are blinking. What could be causing this issue?

Answer

When an Epson L18050 converted to DTF displays a paper jam error with all lights blinking, it is very common that the issue is not an actual paper jam. In many DTF-converted machines, especially those modified from the original Epson design, this error is often triggered by:

• PE sensor problems

• Carriage movement resistance

• Encoder strip issues

• Capping station obstruction

• Firmware/driver board overrides (in professionally converted units)

Let's break these down.

1. PE Sensor (Paper End Sensor) Issues

The PE sensor detects whether paper or film is properly loaded. In DTF conversions, film behaves differently than regular paper, and ink overspray is much heavier. This can lead to:

• Dried ink buildup around the sensor flag

• Film scraps stuck inside the sensor arm

• Misalignment of the sensor lever

• Sensor wiring slightly pulled or pinched during modification

If the PE sensor does not reset properly, the printer will falsely report a paper jam.

What to check:

1. Turn off the printer completely.

2. Unplug it from power.

3. Open the top cover.

4. Inspect the paper path thoroughly.

5. Look near the paper feed entry area for a small black plastic flag (PE sensor lever).

6. Make sure it moves freely and is not stuck with dried ink.

Even a tiny piece of DTF film can block it.

2. Carriage Movement Obstruction

When all lights blink, the printer may also be reporting a general fatal error, not just a paper jam.

DTF printers produce significantly more ink overspray. Over time this can cause:

• Ink buildup on the carriage rail

• Sticky movement along the shaft

• Excess ink accumulation near the capping station

• Mechanical resistance interpreted as a jam

If the carriage cannot move freely from left to right, the printer firmware may trigger a jam or fatal error state.

What to check:

• With the printer powered off and unplugged, gently move the carriage left and right.

• It should slide smoothly.

• If you feel resistance, inspect:

  • The metal guide rail (clean gently if dirty)

  • The capping station area

  • The wiper blade area

  • Any loose tubing from the DTF ink system

Even slight drag can trigger a jam detection.

3. Encoder Strip Problems

The encoder strip is the clear plastic strip behind the carriage that tells the printer where the printhead is positioned.

Common DTF-related issues include:

• Ink mist contamination on the strip

• Strip dislodged from one end

• Strip twisted during conversion

• Sensor misreading due to residue

If the encoder strip signal is lost or corrupted, the printer may:

• Flash all lights

• Show paper jam

• Stop mid-movement

Fix:

Carefully clean the encoder strip with:

• Lint-free cloth

• Distilled water or mild cleaner

Be extremely gentle. Do not scratch it.

4. Capping Station & Pump Resistance

DTF printers produce heavy ink usage. The capping station may become:

• Oversaturated with ink

• Hardened with dried pigment

• Mechanically stuck

If the carriage tries to park but meets resistance at the capping station, the printer may think something is blocking it.

Inspect:

• Capping pad condition

• Waste ink lines

• Pump movement

5. Professionally Converted Units (Driver Board Override)

Some professionally converted DTF printers install a modified driver board that overrides factory sensor logic. In those cases:

• Certain sensors may be bypassed

• Firmware may behave differently

• Errors may appear unrelated to actual mechanical faults

If your printer was purchased pre-converted, check with the conversion supplier to see whether the PE sensor or paper detection logic was modified.

Summary of What Usually Causes This Error

When an Epson L18050 DTF shows:

• Paper jam message

• All lights blinking

It is most often:

✔ False jam from PE sensor blockage
✔ Carriage movement resistance
✔ Encoder strip contamination
✔ Capping station mechanical obstruction
✔ Firmware override behavior

In DTF setups, these are extremely common.

Addressing printer issues can be complicated because they are very hands-on mechanical systems. For this reason, we're unable to provide remote troubleshooting, step-by-step repair coaching, or direct repair support. However, we do offer an in-person diagnostic and repair service at our local facility: BCH Printer Repair Service (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 accept a drop-off.

Our repair structure allows servicing either the complete printer or specific components, with clear intake instructions provided. That said, we recognize that our service rates may not be the most budget-friendly option. Therefore, we strongly encourage self-research first. You can search for detailed walkthroughs on YouTube, especially on our channel homepage: BCH Technologies YouTube Channel (https://youtube.com/@bchtechnologies). Use the search icon next to "About" on the right-hand side of the channel menu to find specific repair topics. I receive dozens of questions daily about whether we have made a video on a certain issue. After nine years of publishing content, it's impossible to remember every video manually. Using YouTube's search tool is the fastest way to locate relevant tutorials. Additionally, YouTube may recommend helpful videos from other creators that can assist you.

Thank you again for reaching out and for supporting our work. We truly appreciate your trust and engagement.