Epson WF-4640 Dumps Cyan Ink on Rail and Displays “Call Epson Support” Without Error Code – Causes and Solutions

Question:

What causes an Epson WF-4640 to dump cyan ink on the rail at startup and immediately display a “Call Epson Support” message, even though no specific error code appears? This issue showed up when inspecting a customer's printer, and it's the first time I've encountered this problem.

Answer:

Cyan Ink Dumping on the Rail

When cyan ink is found dumped on the carriage rail at startup, there are several mechanical causes to consider:

• Damaged or misaligned printhead: If it has been compromised, it can erratically release ink during priming.

• Ruptured damper or leaking cartridge: The damper is part of the internal ink regulation system. A rupture or seal failure may cause pressurized ink to escape onto the rail.

• Backpressure or improper transport: If the printer was stored incorrectly or transported on its side, internal pressure shifts may force ink out when the system repressurizes during power-up.

• Ink purging malfunction: The pump or purge unit might fail, forcing ink out instead of drawing it into the waste pads.

"Call Epson Support" With No Error Code

The absence of a specific error code often indicates a critical failure detected during the initial self-check routine. The printer's firmware may recognize a condition from which it cannot safely recover.

Possible reasons include:

• Electrical short in the carriage PCB or printhead: Ink leaking into the electronics can cause immediate shorts that trigger protective shutdowns.

• Sensor failure: If a key sensor (e.g., for head temperature, carriage position, or ink system) isn’t communicating properly, the printer may trigger a general service call message.

• Corrupted voltage regulation or shorted driver IC: These failures can stop the printer before displaying typical error codes like 0x9A or 0x97.

Because the printer halts almost immediately after startup, this suggests the error occurs during one of the earliest diagnostic steps, often related to printhead power-up or sensor initialization.

What You Can Check:

While you've already started an inspection, here are specific steps that could narrow down the root cause:

1. Inspect beneath the printhead carriage:

   • Look for any pools of wet ink, especially around the printhead ribbon cables and carriage board.

   • Wet ink on electronics can bridge circuits, causing immediate faults.

2. Disconnect and examine the printhead flex cables:

   • Check for ink contamination, corrosion, or burnt traces on the connector pins.

   • Clean with high-purity isopropyl alcohol if ink is found.

3. Visually inspect the mainboard and carriage board:

   • Look for fluid damage, particularly darkened or oxidized spots.

   • If damage is severe, board replacement may be required.

4. Temporarily bypass cyan channel (if possible):

   • Disconnect or isolate the cyan ink line and run a startup test.

   • If the message changes or the printer proceeds further into boot-up, this isolates the problem to the cyan channel.

As we proceed with a complete diagnostic on your unit, we’ll determine if the printhead, carriage electronics, or mainboard has been compromised. Once the affected component is confirmed, we’ll provide repair options and cost estimates.

A Note on Support and Resources

Addressing printer issues can be a complicated affair due to the hands-on nature of the problems. So, we cannot provide remote troubleshooting, suggestions, or support for printer repairs. We offer an in-person evaluation and repair service via our local diagnostic facility (https://bchtechnologies.com/printer-repair-service). Given the high demand, we operate on a first-come, first-served basis. So, it might take a few weeks to get your printer to drop it off. Our services are structured to repair a whole printer or specific parts, with clear instructions on how to proceed. However, we acknowledge that our rates aren't the most economical. Thus, we highly recommend that you resort to self-help via online research. You can start by checking out YouTube or visiting our YouTube channel's homepage (https://youtube.com/@bchtechnologies). Look for specific videos using the search icon next to "About" on the right-hand side of the menu bar. I receive dozens of queries every day asking about videos for specific topics. Having created videos over the past nine years, it's challenging to remember every single one. Therefore, using YouTube's search function would be most efficient. Plus, YouTube might suggest relevant videos from other channels that could assist you.