Fixing Epson "Fake Paper Jam" Errors (Like 000031) Caused by Carriage Movement and Firmware Issues

A "paper jam" message on an Epson printer can be one of the most frustrating errors because it often appears when there is no paper stuck anywhere. In many cases, what you are seeing is a false paper jam-a situation where the printer's internal sensors detect something out of range and the firmware assumes paper is blocking a mechanism.

This post walks through a practical troubleshooting path using an Epson ET-8550 style mechanism as an example. Although models vary, the logic of how Epson detects jams is very similar across many EcoTank and Expression units. We also have a video below to show how it's done.

What a "Fake Paper Jam" Looks and Sounds Like

False paper jam errors often show up during startup or right after the printer tries to initialize the printhead carriage. You may notice a pattern like this:

• The printer boots up and the carriage moves partway.

• It pauses briefly, then moves back.

• It tries the motion again.

• On the second attempt, you may hear a screeching or grinding sound.

• Then the printer throws an error such as 000031, commonly labeled as a paper jam.

That screeching sound is an important clue. Usually, it means the carriage motor is trying to move the printhead assembly, but something is preventing normal travel or the control system believes the carriage is somewhere it is not.

Why Epson Throws a Paper Jam Error When Nothing Is Jammed

Epson printers rely on multiple sensors to confirm that parts are moving correctly. When the printer starts up, it checks several "known positions" and expected movements. If a sensor reports an unexpected value-too early, too late, or not at all-the firmware often defaults to "paper jam" because the most common physical reason for movement failure is an obstruction.

In other words, Epson frequently treats any out-of-range sensor reading as "something must be blocking the path." That is why a huge portion of repair cases get labeled as paper jam even when the root cause is mechanical alignment, a station lock, a position encoder issue, or (in some cases) corrupted firmware.

Check #1: Confirm the Carriage Can Reach the Right-Side Home Boundary

One of the first mechanical checks is simple but critical: does the printhead carriage park all the way to the right and touch the right frame boundary?

The printer establishes a reference point by traveling to the right boundary. If it cannot reach that boundary (or fails to detect it), then every subsequent position calculation can be wrong. As a result, when the carriage later moves left, the printer may "think" it has more travel space than it really does. That mismatch can lead to:

• the carriage running out of room,

• belt slip or strain,

• and that harsh screeching sound.

So first, inspect the right side travel path:

• Look for debris, loose parts, or broken plastic blocking the carriage.

• Verify nothing is physically preventing the carriage from contacting the right side.

• Make sure the motion is smooth (with power off) and does not bind.

Even a small obstruction or a shifted frame piece can stop the carriage just short of the boundary, and that alone can trigger a false jam.

Check #2: Inspect the Capping Station Drive and Lock-Related Gears/Levers

Next, focus on the capping station area. The capping station is the assembly that seals the printhead when idle and often includes pumping and cleaning functions. During startup, the printer may need to lower or raise parts of that station and release carriage locks.

If a key lever or gear in the station drive is broken, the station may not lower correctly. Consequently, the printhead carriage can become mechanically locked in place. When the motor tries to move a locked carriage, you can get:

• a screeching or grinding noise,

• repeated attempts to move,

• and then a "paper jam" error because the expected motion did not happen.

What to look for:

• Broken lever arms or switch-actuating tabs.

• Gears that are cracked, missing teeth, or not engaging.

• A station that does not move through its normal range.

If the capping station cannot lower, the carriage may not be able to move freely. Therefore, a "paper jam" message can actually be a station-lift/lock failure.

Check #3: Clean and Evaluate the Clear Timing Belt (Encoder Belt)

Many Epson printers use a clear belt behind the carriage-often called a timing belt or encoder strip/belt depending on the model's design. Its job is to help the printer determine the carriage position accurately.

If this belt is dirty, smeared with ink, scratched, or damaged, position feedback can become inconsistent. As a result, the printer may misinterpret carriage position and throw errors during initialization.

Action steps:

• Inspect the clear belt for ink mist, sticky residue, or scratches.

• Clean carefully using appropriate methods for delicate plastics (avoid harsh solvents).

• If the belt is badly damaged, replace it rather than forcing repeated cleanings.

Because the printer depends on accurate position information, a compromised belt can cause behavior that looks like a jam even though the paper path is clear.

Check #4: Understand APG Height/Stage Issues and Carriage Interference

Another common cause of false jam symptoms involves the APG mechanism (often related to adjusting the head-to-paper gap or carriage height/positioning behavior). When parts of this system break or go out of alignment, the carriage can catch, stop moving, or fail a calibration sequence.

When a small lever or associated structure is broken, it may:

• protrude into the carriage path,

• catch during travel,

• or prevent the carriage from completing its normal movement checks.

Some units may have had that lever previously modified or removed to bypass repeated stalls. While that can restore motion temporarily, it can also create a new problem: the printer may still "expect" a lever action or state change during its startup calibration. In that case, the carriage might move smoothly, but the logic sequence fails-so you still get a jam error without obvious binding.

The key takeaway: A printer can fail startup checks even when the carriage moves freely if the APG-related expected behavior no longer matches reality.

When the Mechanics Look Fine: Recognizing Firmware or EEPROM Corruption

Sometimes, you do all the mechanical checks-right boundary travel, capping station movement, belt condition, APG clearance-and the printer still behaves irrationally. One telltale sign is when the carriage moves in an unexpected direction during a moment when it should be doing a standard routine.

For example, during a certain step the machine should drive the carriage right, but instead it tries left as if the control logic "flipped." If position sensing appears accurate and consistent, yet the printer attempts the wrong motion at the wrong time, you may be dealing with firmware corruption.

Many Epson mainboards store firmware and operational data on EEPROM/flash chips (commonly SPI flash chips in the W25Q family). These chips have write-cycle limits and can develop bad sectors. If critical firmware sections degrade, the printer can start making incorrect decisions even though the motors and sensors are physically capable.

At that point, a simple software update might help temporarily. However, if the memory chip is physically failing, rewriting firmware onto a failing chip can result in recurring issues-because the underlying storage cannot reliably hold or retrieve the data.

Two Repair Paths: Mainboard Service vs. DIY Chip Programming

Once you suspect firmware storage corruption, there are typically two practical paths forward.

Mainboard Repair Service

If you want the most straightforward route, you can remove the printer's mainboard and have it repaired by a specialist. This approach is often best when:

• you want reliability without purchasing tools,

• you prefer not to solder or program chips,

• or you need professional validation of the board condition.

As referenced in the workflow, you can find repair support through BCH Technologies (bchtechnologies.com). In many cases, the process involves removing the mainboard with basic tools, shipping it for repair, and reinstalling it when returned.

DIY EEPROM/Flash Chip Replacement and Firmware Rewriting

If you prefer a hands-on approach, you can replace (or reprogram) the firmware storage chip(s). This usually involves:

• locating the correct chip type (for example, W25Q128 variants are common),

• removing the original chip from the board (or using a clip/adapter depending on board design),

• programming a known-good binary dump to the correct chip position,

• and soldering the chip back onto the board if needed.

Common DIY requirements include:

• a compatible programmer,

• an SOP8 to DIP8 socket adapter (or equivalent),

• careful orientation (pin 1 alignment is critical),

• and verification after programming.

Verification matters because a failing chip may appear writable but fail read/verify operations at specific addresses. If verify repeatedly fails, you are likely seeing a physical chip problem rather than a simple corrupted file.

This repair path can work extremely well, but only if you follow ESD-safe handling, confirm orientation, and use correct firmware dumps for the exact board/chip location.

Video Walkthrough (So You Can See the Steps Clearly)

Reading a process helps, but seeing the motion patterns and repair steps makes diagnosis dramatically easier. We have a video below to show how it's done, including what the false jam behavior looks like, what to inspect mechanically, and how firmware-chip repair can restore correct startup behavior.

Wrap-Up: How to Decide What to Fix First

False paper jam errors are rarely random. Instead, they usually fall into a few buckets. Start with mechanical basics because they are the fastest to confirm: ensure the carriage can home properly to the right boundary, confirm the capping station can move and release locks, and verify the timing belt/positioning system is clean and intact. Next, evaluate APG-related interference or missing lever actions that can break calibration logic.

If the printer's movements become illogical-especially if it drives the carriage the wrong direction at a key step-then shift your focus to firmware storage health. At that stage, a mainboard service through BCH Technologies or a DIY chip-programming approach can be the most direct route to a lasting fix.