1. Common Abnormal Conditions of Sprinkler Printhead

Seeing something like this on your prints?

Common question: “Is this caused by the ink? The software? Or something wrong with the printer?”

In most cases, it’s simply a blocked or poorly maintained printhead.

The whole print appears with missing or faded colors.

There might be a partial blockage or poor flow in the nozzle.

There are lines or vertical streaks in the print.

The nozzle might be partially blocked or have poor ink flow.

White ink did not fully cover the color image.

The white nozzle might be partially blocked or have poor ink flow.

DTF Powder appears in the blank areas around the design on the DTF film.

Ink splatter caused by misfiring nozzles—ink sprays at an angle and lands outside the design area.

Nozzle test print shows broken or missing lines

Ink Splatter–Lines Are Not Straight

Example of a nozzle test with misfiring: the lines are not straight and appear shifted or angled.

Ink Splatter

Ink Splatter Caused by Angled Spray

Nozzle Test–Ink Splatter

Normal Nozzle Test – All Lines Complete and Continuous

If your printhead has been used for over 10 months, seeing 3–5 minor broken lines on the nozzle test after cleaning is considered normal.

Printheads are high-value consumable parts, and over time, some nozzles may show signs of aging or partial clogging.

As highlighted in red, 3–5 minor breaks are expected and don’t affect printing.

2. Common Causes of Nozzle Abnormality: What’s Happening Behind the Scenes?

3. What Should We Do First?

Always Start by Printing A Nozzle Check Test

This tells you clearly:

• Which color channels are printing normally
• Which nozzles are clogged or not firing

Then follow this step-by-step guide:

4. Printhead Troubleshooting Guide

If your nozzle test shows broken lines, missing colors, or white ink not covering properly, follow the steps below to identify and fix the issue.

4.1 Step 1 – Print a Nozzle Check

4.1.1 How to Do It

• Step 1: Click on “PrintExp_X64” to open the printing software interface. (Example based on LINKO A-602. For other models, please refer to the corresponding guide.)

• Step 2: Click the “Check” button to print the nozzle test.

• Step 3: Look at the printed test pattern to evaluate the condition.

4.2 Step 2 – Clean the Printhead

4.2.2 How to Judge

✅ Test looks normal now: You’re done!
❌ Still has broken lines: Continue to step 4.3 to soak the printhead.

Normal test strip diagram

Test strip disconnection diagram

If the test strip is not broken, it means there is no abnormality and do not continue. If the test strip is still broken or lacks ink, go to step 3.

• Step 4: Carefully drop the fluid onto the captop sponge pad under the printhead.
  (Just enough to wet the sponge—do not overfill or let it leak.)

The captop sponge pad

Dropping cleaning fluid

• Step5:
• Click “X Reset” to return the printhead to home position.
• Wait for 10–15 minutes so the fluid can soak and loosen clogs.

Note: Do not soak the printhead for more than 30 minutes to avoid damaging it.

“X Reset” – Return Carriage to Home Position

• Schematic diagram of the carriage returning to its original position (observe whether the printhead fits the ink stack, and ensure that the printhead fits the ink stack)

• Make sure the printhead sits tightly on the captop.

Carriage Returned to Home Position

• Step 6: After soaking, clean the printhead again (“Clean”) and re-check (“Check”).
  Click “Clean” → Select “2 Head – All” → Choose “Clean Normal”
  ➜ The printer will clean both printheads automatically (1–2 times recommended)

Software Cleaning – Click Steps

• After cleaning, click the “Check” button to print a new nozzle test.

Nozzle Test Print

• Complete diagram of the test strip:

Example of a Complete Nozzle Test

If the test strip is not broken, it means there is no abnormality and do not continue. If there is a break, go to step 4.

4.3.3 What to Look For

✅ If the test looks good after this step→ The issue is resolved.
❌ If the test still shows issues →, move to step 4.4 to check the ink system.

4.4 Step 4 – Check Ink Tube Connections

Make Sure Ink Flows Smoothly Without Leaks

4.4.1 Go through the checklist below step by step:

Check the ink tube connection, observe whether the ink tube valve is open (make sure the valve is open) and make sure the ink sac is tightly connected to the nozzle without looseness or ink leakage.

Rear ink tube connection (to ink tank):
➜ The tube should be fully inserted and aligned properly with the ink tank to prevent leaks.

Is the ink valve open?
➜ Make sure the valve is fully open. A closed valve can cause ink flow issues or nozzle gaps.

Ink Valve Open

Ink Valve Closed

4.4.2 Checking Ink Tubes and Removing Air Bubbles

There are two ways to remove air: software-based ink loading (recommended first) or manual suction using a syringe if needed.
If you performed any of the following actions:

• Replaced the ink dampers
• Reconnected or adjusted ink tubes
• Found loose ink tube fittings

Air may have entered the system. This can block ink flow and cause missing colors or nozzle gaps.
That’s why it’s critical to both check the tube connections and remove any air inside before continuing.

4.4.3 Method 1 Remove Air via Software (Recommended)

Step①: Open the printing software and go to the main menu →Click on “Load Ink”，The printer will begin drawing ink automatically.

After running “Load Ink,” go back to the main screen and clean the printhead again:
Click “Clean” → Select “2 Head All” → Choose “Clean Normal”,Then run a nozzle check (“Check”) to see if the test pattern is normal (1–2 times recommended):

✅ If the nozzle test is complete with no broken lines, the issue is resolved — no further action needed.

❌ If broken lines still appear, proceed to 4.4.4 Method 2 Manual Air Removal.

Step③: Gently insert the syringe into the damper outlet and slowly pull to draw ink and air out；release the drawn ink into the waste ink bottle. Check the ink lines to ensure air has been fully removed.

Note:
❌ Do NOT squeeze the damper in the middle – this may cause ink to spray out unexpectedly
✅ Hold the damper from the sides for safe and stable handling

Incorrect Handling – Squeezing the Center (Do Not Do This)

Correct Handling – Holding Both Sides

Step 5: Replace the ink cartridge (if necessary)

4.4.5 Replacing the Damper (If Needed)

Check whether the ink bag is filled with enough ink and whether it is leaking due to aging. If the ink bag is aged or damaged, you need to replace it with a new one.

Start by checking the damper:

• Make sure it is properly filled with ink
• Check for any signs of aging, air leakage, or physical damage

If the damper is leaking, cracked, or very old, it should be replaced with a new one.
If you have already completed all previous steps and the nozzle test still shows broken lines, the damper might not be working properly.

After replacing the damper or confirming it’s in good condition, if the problem still exists, please contact your dedicated LINKO technical engineer or sales advisor for further support and diagnosis.

Keep Your Printhead in Top Condition
Regular cleaning and proper maintenance are key to extending the life of your printhead and ensuring consistent print quality.
Neglecting daily care can lead to clogs, misfiring nozzles, or even permanent damage.
Click here to learn how to properly clean and maintain your printhead every day
[Go to Printhead Maintenance Guide →]

Want to avoid future problems before they happen?
Learn how to set up a preventive maintenance routine and reduce printhead failures.
[Go to Preventive Maintenance & Troubleshooting Tips →]