Why an Epson TX800 UV Printer Prints Blank Even Though the Nozzles Flush Ink: Q&A Troubleshooting Guide

Question

A user operating a UV printer equipped with an Epson TX800 printhead reports that the printer produces no ink during printing. However, when flushing the printhead through the software utility, ink flows normally. They have already replaced multiple components-specifically the headboard, FFC cable, and the printhead-as recommended by the manufacturer. They ask whether these are indeed the correct parts to replace and whether they can send in components for inspection and repair.

Answer

Why Your TX800 Flushes Ink but Prints Blank

Your observation-that the printhead can flush ink but cannot print-is extremely important because it confirms that:

• The printhead nozzles are not clogged

• Ink delivery to the head is functional

• The head can fire ink under flush mode

This narrows the issue to the control system, not the ink system.

Below are the key areas that can cause this exact behavior.

1. Printhead, FFC Cable, and Headboard (Your Manufacturer's Suggested Trio)

Your manufacturer recommended replacing three main components:

• Printhead

• FFC / flat flexible cable

• Headboard / carriage board

These are indeed the three most common failure points when a TX800 prints blank.

Why these parts matter:

• The headboard supplies the firing signals and voltage to the printhead.

• The FFC cable carries the data signal from the mainboard to the headboard.

• The printhead must receive both stable data and stable voltage to fire ink during printing (different from flush mode).

If any of these three fail, you can get:

• Blank prints

• Missing ink in print mode but successful flushing

• Intermittent firing issues

• Error codes such as:

  • "Printhead Voltage Error"

  • "Carriage Communication Error"

  • "Printhead Temperature Error"

So yes-your manufacturer's recommendation is reasonable.

However... these are not the only possible causes.

2. Mainboard (Logic Board) Problems

This is one of the most overlooked causes.

Your UV printer's mainboard controls the firing sequence. If parts of the mainboard fail-especially the printhead driver ICs-you may see:

• Ink firing during flush mode

• Zero firing during print mode

• Sudden blank prints

• No error codes at all

Flush mode uses a different electrical pattern than normal printing, so a damaged firing transistor or power regulator may still allow flushing but block printing.

3. Printhead Overtemperature Protections

TX800 heads include thermal protection. If the firmware detects:

• High internal temperature

• Faulty temperature sensor

• Incorrect head voltage

• Failed thermistor reporting false heat levels

...the printer may prevent ink firing to protect the head.

This often results in:

• Successful flushing

• No firing while printing

• Nozzle check pattern showing blank output

• Occasional "Head Overheat" or "Temperature Error" messages
  (though some UV firmware hides temperature errors)

4. Dampers, Ink System, or Negative Pressure Issues

Even if ink flushes, you can still get firing failure if:

• The damper is defective

• Air is trapped in the damper

• Negative pressure is too high or too low

• The ink pump or cap station is malfunctioning

However, this usually causes banding or missing lines, not complete blank prints-so this is less likely in your case.

5. Incorrect Firmware or Print Mode Configuration

On third-party UV printers, it is surprisingly common to see:

• Incorrect waveform settings

• Incorrect head voltage in firmware

• Wrong firing frequency

• Corrupted head parameters

When the waveform does not match the TX800 firing requirements, the head may flush but refuse to fire droplets during printing.

So Is Your Manufacturer Correct?

Yes and no.

✔ Yes - those three parts are commonly responsible.

The headboard, FFC, and head itself are legitimate failure points and often the first components to check.

✖ No - they are not the only responsible components.

Many UV printer failures originate from the mainboard, head driver ICs, temperature sensor issues, or firmware configuration, none of which are solved by replacing just those three parts.

Regarding Sending Parts for Inspection

At this time, I am not able to take in external components for diagnostic evaluation. The issue can involve multiple interconnected systems, and board-level repairs require a complete working unit for proper testing. However, I can refer you to a specialist who does handle individual TX800 component repair if you would like further assistance.

Important Notes on Printer Repair Services

Addressing UV printer issues-especially with components like TX800 heads-requires hands-on inspection and very controlled diagnostic procedures. Because of the nature of these repairs, we're unable to provide remote troubleshooting or step-by-step repair guidance. However, we do offer in-person evaluation through our Printer Repair Service (https://bchtechnologies.com/printer-repair-service). This service operates on a first-come, first-served basis and may require a few weeks before intake. We repair full printers or individual assemblies, depending on the issue.

Our repair rates are not the cheapest option, so we highly encourage checking online resources for self-help. A great starting point is the BCH Technologies YouTube channel (https://youtube.com/@bchtechnologies). You can search for specific topics using the search icon next to the "About" tab. With nine years of videos, it's impossible to recall them all, but YouTube search will guide you to the right content-including helpful videos from other creators.

Thank you again for reaching out and for your patience. We truly appreciate your trust and support, and we hope this information helps guide your next steps. If you have further questions, feel free to reach out anytime.