Ink tube torn – Printer Cleaning Issues Part 11 ARTJET 2026

• When ink enters the Damper from the main ink bottle via the ink tube, it passes through the print head, flows to the captop, moves through the motor pump, and finally drains into the waste ink bottle.
• This article covers the Ink Tube Burst section of the full ink supply problem series.
• This follows Part 1 Captop Lower Tube, Part 2 How to Replace the Captop, Part 3 Damper, Part 4 Pump Motor and Yellow Tube, Part 5 Captop and Head Position, Part 6 Aligning the Captop and Head Position, Part 7 When the Capping Station Level Is Not Correct, Part 8 Captop Surface Drying, Part 9 Degraded Ink Inside the Captop, and Part 10 Time for Ink to Fill the Damper.

Colors not coming out properly during printing

• Many people clean the head and press the Test button to check for missing nozzles.
• However, if colors look abnormal during printing, you should press the TEST button immediately after the print — without cleaning — to identify which color is affected.

What the customer did when the problem occurred

• After printing, the nozzle pattern was printed without cleaning — the Black ink nozzle pattern did not appear
• Inkload (pumping) worked fine with ink flowing smoothly into the waste ink tank, and no specific problems were observed during cleaning
• However, Black ink did not come out properly when printing the nozzle pattern
• A few nozzle streaks appeared along with thick bars — this means the electronic board and head (DATA) are not the issue
• This is an ink supply problem that needs to be investigated

“For color inks, the ink lines connect 1:1 to individual ink tanks, so even if Black isn’t printing, inkload (pumping) can still work fine with the other inks. Let me check the ink supply step by step.”

Assumptions when only the Black channel has a problem

• A few nozzle streaks are appearing in the Black channel, so this is not a head or electronic board (DATA) issue
• Inkload (pumping) is working properly, so the area below the Captop is operating normally

Since only one channel’s ink supply is affected, the following items need to be checked

• Damper connection status on top of the print head
• The damper itself (occasionally, dampers have been found with tears)
• Tightness of the ink tube inserted into the damper
• Possibility of air entering the ink tube between the damper and the main ink tank

• The customer pressed the damper firmly to ensure it was properly seated in the head, but the problem persisted
• The ink tube connected to the damper was also tight and difficult to remove when pulled by hand. The same issue continued

If the damper is properly seated and the ink tube is tightly connected, the next step is to use a syringe to check the section above the damper.

• To check the Black ink supply from the main ink tank to the damper, the customer removed the Black ink damper and pulled with a syringe — ink flowed smoothly
• After cleaning, a much better nozzle pattern was achieved
• This appeared to resolve the issue, but during the next print job, Black ink stopped printing again, and the nozzle pattern once again failed
• When the customer tried pulling Black ink with a syringe again, no pressure was felt at all

Upon arrival at the site, we pulled the damper with a syringe, but no pressure was felt. Only a small amount of ink and air was drawn.

A. Ink line inspection

First, we inspected the ink tubes and various fittings in the ink line shown in the photo below, but no problems were found.

B. Ink tube inspection below the board

• The electronic board was removed as shown in the photo below
• After disconnecting the main ink line coming from below the electronic board and inserting a syringe into the cut end (indicated by the arrow), only air was drawn
• This confirmed that air was entering from somewhere in the main ink tube running from the main ink bottle through the cable carrier

C. Resolution

• The problem was resolved after replacing the entire Black ink tube connected from the main ink bottle through the cable chain
• The burst ink tube is shown in the photo below
• This was the first occurrence in 4 years, and it happened at a high-volume production site

D. Ink Tube Replacement Workflow

• While you are unlikely to need to replace it yourself, the complete workflow is documented here.
• With the power on, raise the head height and move the head carriage toward the flatbed.
• Turn off the GUI → turn off all buttons on the touch panel including the Power button → turn off the printer’s main switch. The head carriage can now be moved by hand.
• Remove the printer cover. For cover removal instructions, click here. Refer to the photos in the middle of that article.
• Disconnect the DATA cables for all three print heads and loosen the screws on the carriage board. Once the head carriage board is removed, the ink lines underneath become visible.
• Remove the tape attached to the ink tubes coming from the cable chain. Then cut the defective ink tube.
• Empty the main ink tank for the affected color and cut the tube directly underneath to separate it. Remove the bottom cover of the main ink tank.
• Connect the replacement ink tube (at least 2.5 meters) to the separated ink tube using a straight-through fitting.
• The color ink tubes are separately bound with tape where they enter the cable chain. Remove the tape.
• The new ink tube is now connected to the defective tube via the straight-through fitting. Since the tape binding the color ink tubes has been removed from both the head carriage section and the cable chain section,
• the defective ink tube can now be manually pulled from the bottom of the carriage board.
• Even when pulling, the defective ink tube will not come off easily.
• Try pulling the ink tube while moving the head carriage. If it still won’t come off, detach one section of the cable chain (it will be damaged), peel off the black protective film, and gently pull out the defective ink tube.
• Then pull again — the defective tube will come free.
• Connect the new tube to the cut end using a straight-through fitting.
• Reassemble in the reverse order of disassembly to complete the process.

When a specific channel on a color print head stops printing during a job, it is almost always an ink supply issue for that channel.

Ink flowing into the waste tank during inkload (pumping) does not mean the affected channel’s ink supply is working — other inks are being pumped, so inkload can appear normal even when one channel has failed.

• First, press the damper by hand to ensure it is properly seated in the print head. If the problem persists,
• Second, remove the damper from the print head and use a syringe to pull ink — check that it flows smoothly without air bubbles.
• If ink comes out with air bubbles, check the connection between the damper and the ink line.

If only air is drawn when pulling with the syringe, check the following:

• Is the damper itself torn? (We have experienced this a couple of times.)
• Is the tubing slightly loose in the fitting? Is the fitting itself cracked? (This has happened only once so far.)
• Is the ink tube torn somewhere in the middle?

You can diagnose the issue by disconnecting the ink line sections one by one starting from above the damper, bending each section by hand, and pulling with a syringe to check for air ingress.