Firebird ink Knowledge Base

Where Did One of My White Ink Channels Go?

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Why is My DTG Ink Channel Not Working?

It is frustrating when something that has been working well for a while suddenly decides to cease functioning for no apparent reason. However, there is always a reason, whether we understand it or not.

Most offices are absolute bee-hives of activity. This sporadic printing activity is typically the root of many daily headaches. The most common of these issues is the dropping out of white ink channels. Although every DTG machine varies from company to company or model to model, the overall concept is the same. Deliver ink from the source to the print heads and produce awesome looking t-shirts that help pay for the machine and make your business grow. While this sounds simple enough, there is plenty of room for problems to develop.

When the printer is not performing as it should, a simple process can turn into a major frustration. Many users may run a simple head clean or two to get the channel printing again. Hopefully, this is the only fix you need. However, when head cleans are not solving your problem, it is time to dig in deeper.

The Most Common Reasons for a Channel Dropping Out

One of the most common reasons for a channel to drop out suddenly is that air has been introduced into the print lines. When the air in the lines is minimal, a head clean or two can resolve this. When multiple head cleans do not seem to help, the air problem is likely more than just bubbles in the lines. This was the case in the example that we will be looking at on FIREBIRD’s own Anajet mP5i.

anajet-mpower-dampers1With our experience across a wide range of printers, we have a better sense than most of what components could attribute to the problem. In many printers, the first place to look would be the dampers. In most DTG printers, the ink lines go from the source to a damper dedicated to each color. The line connected to the damper should have an “o-ring” on it so that when the brass nut around the ink line screws onto the damper, the o-ring blocks air from entering the system. Checking these connections and the condition of the o-rings may resolve an air leak.

We were not so lucky in our case, so we had to look for other possible solutions.
nva-screw-locations1The AnaJet mPower series DTG printers incorporate a re-circulation system for the white ink lines to help prevent settling in the white ink. The white ink channels use a slightly different needle valve assembly than do the CMYK channels. We have found that white ink builds up inside this valve over time and is often the cause of white ink channels dropping out. Fortunately, this is a simple fix. The only tools I will needed are a phillips screwdriver and (possibly) an old tooth brush.

The first thing to do is power down the mPower printer. Locate which channel is not printing (for the mP5 there are only two). The 1 st white channel (or inside channel) was the problem in this case. Remove the ink cartridge from this location. There is a small PCB just above the area that needed work to resolve our issue. This PCB is easily removed by gently lifting up on the sides, one at a time and the board will pop free. I did not find the need to disconnect anything from this board. I was able to just rotate it out of the way.

Using a phillips screwdriver, remove the two silver color screws that hold the needle valve assembly (NVA) in place. One is at the bottom left corner the other is at the upper right. The entire block is now free and can be pulled away from its mounting location. On the same side of the NVA are two more black phillips screw heads. Removing these will open up the NVA. Use caution to not lose the small hex nuts on the back side of these two screws.

With the NVA now open, it was apparent that white ink had built up on the bottom portion of the inside valve area. Using an old tooth brush, I simply brushed away the ink deposits and wiped this half of the assembly with a clean cloth. I took the other half of the assembly to the sink and thoroughly rinsed all of the components and then wiped them down with a clean cloth prior to re-assembling the two halves.

After re-assembling and re-mounting the NVA, I ran two head cleans and my white was completely back to where I had expected it to be.

Understanding the root cause of my problem and being able to fix it simply had me back up and running in no time. I will now implement a monthly inspection of the NVA as preventative maintenance.

In our next instalment, we’ll talk about other preventative maintenance procedures needed for an enjoyable summer vacation.