How to Replace a Mutoh XpertJet 1641SR Print Head: Step-by-Step Guide

How to Replace a Mutoh XpertJet 1641SR Print Head: Step-by-Step Guide

A failed print head on the Mutoh XpertJet 1641SR brings your entire production to a halt. Whether you're dealing with persistent missing nozzles, ink cross-contamination, or a front-panel replacement alert, this guide walks you through the full process — from confirming the head truly needs replacing, to running your first clean nozzle check after installation.

First: Confirm the Print Head Actually Needs Replacing

Many symptoms that look like a dead print head are actually caused by worn dampers, a clogged capping station, or a degraded wiper blade — all significantly cheaper fixes. Before ordering a new head, check for these signs:

  • Multiple missing nozzle rows that persist even after 3–4 power cleans and a manual head soak
  • Ink cross-contamination between colors — one channel bleeding into another, visible on a nozzle check print
  • Head replacement alert on the front panel — the XPJ-1641SR tracks usage and notifies you when the head reaches its rated life
  • Visible ink leaking from the print head body — pooling on the carriage plate beneath the head
  • No improvement after replacing dampers and the capping station — if new parts didn't fix the issue, the head itself is the cause

If you haven't yet replaced your dampers and cap top, do that first. A fresh set of dampers resolves the majority of nozzle issues on the XPJ-1641SR at a fraction of the cost of a new print head.

What You'll Need Before Starting

Gather everything before opening the printer. Having to stop mid-replacement with the carriage exposed risks ink drying on the new head before you even finish installation.

  • Genuine Mutoh print head assembly for the XPJ-1641SR
  • Phillips screwdriver
  • Round-nose pliers
  • Mutoh cleaning solution
  • Lint-free swabs and cloths
  • Full set of fresh ink bags
  • Nitrile gloves
  • New damper set (strongly recommended)


Always use a genuine OEM print head for the XPJ-1641SR. Compatible third-party heads may appear to work initially but frequently cause banding, color shifting, and early failure. The original Mutoh head is calibrated to your printer's exact voltage and drop-size profile.

 

 

Step-by-Step Replacement Procedure

Step 1

Flush the ink system before removing the head
  • From the front panel, navigate to the Longstore function in the setup menu
  • Load bags of cleaning solution as prompted — the printer will automatically flush all ink channels
  • Once the flush cycle confirms completion, power off the printer using the main power switch, not the soft panel button

TIP

This step protects your ink supply lines and makes the head removal process much cleaner and safer.

 

Step 2

Move the carriage to the service position
  • Power the printer back on and navigate to the Head Replacement option in the service menu — this moves the carriage to the center of the platen where you can access it comfortably
  • Once the carriage is in position and the panel confirms it is locked, power the printer off again using the main switch
  • Open the front cover and carriage cover to expose the print head

CAUTION

Never manually push the carriage with the printer powered on. Always use the service menu to position it. Forcing the carriage can damage the encoder strip and carriage motor.

 

Step 3

Disconnect the flex cable and ink tubes
  • Locate the flat flex cable running from the carriage board to the print head. Gently lift its locking lever and slide the cable free — use your fingers, not tools, to avoid tearing it
  • Using round-nose pliers, squeeze and release the spring clip on each ink tube joint at the damper-to-head connection, then pull the tubes free
  • Place lint-free cloths beneath the disconnected tubes to catch any drips

TIP

While the head is off, inspect your dampers closely. If you see air bubbles, discoloration, or membrane deformation, replace them now — it's the perfect time.

 

Step 4

Remove the old print head
  • The head is held to the carriage plate by two mounting screws — unscrew both fully
  • Carefully lower and slide the head out of its cradle, supporting it from below as it releases
  • Seal the old head in a bag immediately to contain any remaining ink

 

Step 5

Clean the carriage seat
  • Use a lint-free swab dampened with cleaning solution to wipe the head mounting area — remove any dried ink or residue from the carriage plate
  • Allow the area to dry for 2–3 minutes
  • Inspect the capping station cap seal and wiper blade. A hardened cap seal or splayed wiper is one of the most common causes of premature new head failure — replace them if they show any wear

 

Step 6

Install the new print head
  • Remove the new head from its packaging — handle it only by the sides, never touching the nozzle plate on the bottom face
  • Align the head with the carriage cradle, ensuring the locating pins seat correctly
  • Hand-tighten both mounting screws first to confirm alignment, then tighten firmly — don't overtorque, the carriage plate is aluminum
  • Reconnect each ink tube to the correct color channel on the damper block and push until the spring clip clicks into place. Give each a gentle tug to confirm it's locked
  • Reinsert the flat flex cable fully into the head connector and lock the lever down

TIP

Double-check that each ink tube is connected to the correct color channel (C, M, Y, K). Cross-connecting even one channel will contaminate the new head immediately.

 

Step 7

Register the new head in the service menu
  • Power on the printer and enter the service menu
  • Navigate to the Head ID or Head Registration option and enter the ID number printed on the label of your new print head exactly as shown
  • Save and exit the service menu

NOTE

Skipping head registration means the printer cannot track the new head's lifespan. You'll lose the end-of-life warning that helps you plan maintenance before a failure ruins a production job.

 

Step 8

Charge ink and run a nozzle check
  • Install a full set of fresh ink bags and follow the panel prompts to begin the ink charge cycle — this fills all channels through the new head and takes several minutes. Do not interrupt it
  • Once complete, print a nozzle check from the panel
  • All color rows should fire cleanly. A few gaps right after installation are normal — run 1–2 standard cleaning cycles to clear them
  • If multiple rows are still missing after 2 cleans, check that the flex cable is fully seated and that the dampers are not air-locked

TIP

Run 2–3 nozzle checks before printing a customer job. A new head benefits from a full initial ink flow-through to settle all channels.

 

Step 9

Run bi-directional print alignment
  • From the panel, run the printer's built-in bi-directional alignment calibration utility
  • Load your standard production media and follow the prompts
  • Once the calibration saves, print a test file at your most common print mode before resuming production

TIP

Every new print head sits at a slightly different position on the carriage. Even a small difference causes visible banding or misregistration in bi-directional printing mode — this step is not optional.

 

Final Checklist Before Resuming Production

 

✓

 All ink tubes locked into the damper block (spring clips clicked)

✓

 Flat flex cable fully seated with locking lever engaged

✓

 Mounting screws tightened securely

✓

 Head ID registered in the service menu

✓

 Ink charge completed without errors

✓

 Nozzle check shows all rows firing cleanly

✓

 Bi-directional alignment completed and saved

✓

 Test print approved before first production job

 

Need a genuine print head for your Mutoh XpertJet 1641SR?

House of Parts stocks original Mutoh print head assemblies with global shipping to Singapore, Malaysia, USA, UK and more — delivered within 1–2 business days.

Visit: houseofparts.net/collections/printheads

Frequently Asked Questions

How long does a Mutoh XpertJet 1641SR print head last?

Print head lifespan on the XPJ-1641SR depends on print volume, media type, and how consistently you maintain the printer. In typical production environments, a well-maintained head can last several years. The printer tracks usage internally and will display a replacement notification on the front panel when the head approaches end of life.


Can I replace the print head myself without a technician?

Yes — the mechanical side of the replacement is user-serviceable with basic tools. The steps that require the most care are correctly registering the new Head ID in the service menu and running the bi-directional alignment after installation. If you're unfamiliar with the service menu, consult your Mutoh dealer or supplier before proceeding.


Should I replace my dampers at the same time as the print head?

Yes, and strongly recommended. If your printer has run long enough to need a new print head, the dampers have almost certainly aged too. Installing a new head onto old, degraded dampers is one of the most common causes of early head failure. Replacing both at the same time costs a fraction of the head price and protects your investment.


Why is my nozzle check still showing gaps after installing a new head?

A few missing nozzles immediately after installation are normal — run 1–2 standard cleaning cycles and they typically clear. If multiple rows remain missing after 3 cleans, the most common causes are: the flat flex cable not being fully seated, air-locked dampers, or a capping station that isn't sealing properly. Check all three before assuming the new head is faulty.


Do I need to recalibrate the printer after replacing the print head?

Yes. Every print head sits at a slightly different position on the carriage, and even a tiny difference causes banding and misregistration in bi-directional print mode. Running the printer's built-in bi-directional alignment calibration after installation is essential — it's what ensures your first production print looks correct.

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