Timothy Mitchell with HP Latex.
I want to walk you through an issue that I had recently that I resolved,
and I want to show you how I resolved it,
and the issue was related to printheads that were not printing at all.
So, I, I'll go through the steps here.
You won't be able to see everything, so I'll have to describe some of it to you.
But I think I can illustrate the nature of the problem.
I can show you my process, and then explain how I arrived at what obviously is a successful conclusion.
So, I sent a job over, in this case to the, uh, 335, and the image was printing,
except it didn't seem quite right.
The colors were off.
I couldn't quite see why.
But it didn't appear to have banding per se, but it was almost as if,
uh, something, something in the file went wrong.
So, then what I did is, just to check and make sure all the nozzles were firing,
is I ran a printhead check.
Which is the next print right here.
And in the print head check, it's very clear that black ink is completely gone.
I mean, it's not there, and it's not there in either of the two printheads.
So, you have, I'll try to roll this down as I explain it.
So, you have cyan here.
But there's no black, and it's gone in both printheads.
That's a little unusual.
So, the machine had sat for a while.
I'd been on a, on a, on a bit of a, an extended road trip.
And everything else was fine except the black just vanished.
So, thinking about the black being gone, I thought, well maybe there's something wrong with the ink system.
Because usually if you would, you know, if one of the printheads were bad,
I would expect to see some of the cyan missing.
But both the cyans are perfect.
In fact, every other print head is perfect.
Just the two blacks.
And if it, one was missing, I might think, Ok, that printhead went out the other one is fine.
But to see both missing, uh, I figured I would start with the ink systems.
So, I took the black ink and I said, you know, remove the black ink, and then I put a new black ink in,
and it made no difference.
So as far as the ink container or the vacuum system connected to the ink,
that did not seem to make any difference.
And so, then I figured well, maybe there's a, it can't be a contact issue because the
cyan would be missing, too, what are the chances of both black printheads,
and then I noticed that the maintenance cartridge was almost completely full.
So, I figure, maybe it was something to do with the capping station,
and the black capping station wasn't quite right.
Although that didn't quite make sense with the cyan still being there, but I replaced that anyway.
Made no difference.
It was only three percent left available, so I figured I would just give it a shot.
So now I'm trying to figure out, why do I, you know, just black working?
Now sometimes if a printhead isn't working or the printer's been sitting for,
idle for a extended period of time, if the capping station didn't make full contact,
maybe just running the printer will get everything back up and working.
So, I run a particular chart, and it looks like this.
The chart is designed with pure hues turned on, I'm using ONYX for this,
so I have all the pure hues turned, on and then I also have lightings.
What I want to identify is, if I have a particular color out, I want to know which one,
and then the next thing I'll isolate is, which of the two printheads, if there are two printheads.
If there are, if it's a lighting, there's only one printhead, so obviously, I only have
one printhead to remove or to address, and this is how bad it is.
Every single color is perfect, except black doesn't exist.
Like it's gone.
Both printheads.
I've never seen this before.
So, I do a couple cleanings.
I target the black, I clean it once, I clean it twice, and still I get nothing.
So, the next thing I do is, I'm about ready to replace the printheads.
Because I'm thinking that something went on, and both the black printheads, black and cyan heads,
the black side of it, went out, even though the cyan side is perfect.
That seems highly irregular, but I'll give it a go.
But before I did, I took one of the black printhead, black and cyan printheads, out.
I took a lint-free cloth.
This lint-free cloth is what we normally use to clean UV printers.
You can get it at a printer supply.
And then I took this distilled water here.
Took the printhead out and I soaked the cloth, cleaned around the outside, soaked it again
and folded it and then blotted it on to the printhead.
And since I'm at the point really where I think the printhead is probably dead,
I took a little the distilled water, got it on the printhead, and then kind of wiped it very gently across,
making sure that I wasn't carrying anything from my prior cleanings across the printhead.
I then put that back into the printer, closed the lid,
and then it automatically starts running a printhead alignment test.
The first thing I notice is, voila, one of the black heads is completely back, 100 percent.
The other one is still gone but the one that I just cleaned is 100 percent back.
Huh, ok!
So, then what I did is, well that tells me, let's try it with the other one.
So, I took the other printhead out, did exactly the same thing.
And then it automatically runs a test again.
And once again, now instead of one printhead, now they're both back.
Both blacks are there.
The one down here, one is gone completely.
This one here, both, both black printheads, both black, both of the black sides of both
printheads is working perfectly.
So, then I sent my test pattern again.
And 100 percent perfect solid black.
Everything's back.
There's my cyan, there's my yellow, magenta, black, and then my lightings.
I have two lightings 'cause I'm not sure exactly at what percentage the lighting starts,
so I did two different percentages.
The purpose of this chart, which I use all the time, I keep it handy, is,
before I'm going to do a long run or I'm going to do a big solid run or a big panel job or something,
when I start the printer on Monday, sometimes, if I've been away for a long time,
if I have any question that everything on the printer isn't perfect, maybe I had a head strike,
I will often send this chart, and the chart is actually, each one of these is about, uh,
eight inches by eight inches, and I have them in squares, and if I need to, I just send multiple copies.
You can make your own in Illustrator, it's very easy.
It is 100 percent cyan, 100 percent yellow, 100 percent magenta, 100 percent black, you get the idea.
And those I think I have 'em set for, uh, 25 percent and 15 percent, respectively.
Then when I have pure hues turned on in the RIP, when I send this file over,
it is only going to use black ink to print black.
It's only going to use yellow ink to print yellow, and that helps me diagnose if I think
that I have nozzles missing or something may have gotten onto the printhead,
or some unusual thing has happened.
Like in my case, black vanishes altogether.
With the black vanishing, I now have the black up again.
Now I'm going to run the printer for a while and make sure everything is OK.
But it appears, based on the testing that I've done, that the black ink had just simply,
uh, I don't know what happened, I have no idea.
I don't have a logical answer.
I'm going to reach out to our engineering team and ask.
But clearly there was an advantage to take the printhead, pull it out of the printer,
I was going to toss it anyway, so this is a Hail Mary.
I clean this completely, lint-free cloth, distilled water, not alcohol, clean this printhead,
I get all of my ink back again.
Everything is running fine.
There's no reason to toss the printheads, they only have about 2,500 milliliters through
them, so they haven't had that much ink through them.
They are past warranty, but there's no reason to toss 'em.
For whatever reason, the black just got clogged up on 'em, and it's not firing,
and I just did a manual type cleaning.
And I just wanted to show you the results 'cause it just happened to me and I wanted
to capture it and explain the process.
I do run this chart pretty regularly.
Anytime I think there's something missing, I run the chart.
Now, if you see a bunch of this cyan missing or you have horizontal banding,
then you know it's one of the two printheads.
And that's when I run the print head, uh, diagnostic chart and try to isolate, you know,
which of the two black and cyan printheads is most likely to be the trouble.
You can also check in the embedded web server under the Service tab and it will show you,
if you do all tests, it will show you the printhead tests,
and it will show you which nozzles are out, and sometimes it helps to identify which printhead
by identifying which one has the most nozzles out in a sequence.
Now, in the printer did tell me, by the way, when I sent the job over at the beginning,
the image, it said, you have a printing problem.
You have an image quality problem because the, uh, optical drop detector checked the printheads and said,
bub, you're missing a whole bunch of nozzles here.
There's something really, really wrong and we're going to flag it for you.
Now I could look at the print and see something was wrong.
Obviously, when you send a solid color print, it's obvious that black has disappeared completely,
but the printer did do its job.
It did see that there was something wrong, 'cause when it did the optical drop detection,
it noticed that there was a whole ton of black missing.
It threw me a warning notice.
So, the printer definitely did tell me.
But just running this chart will also confirm whether you're good to go
or whether you need to address the printheads.
So, I'm going to roughly title this manual printhead cleaning "lint-free cloth, distilled water".
I do do this.
If the printhead is very old and it were missing, then I would probably replace the printhead.
But you can always try to reclaim it as a last-ditch effort.
And this probably only took me a half an hour total, including the, uh, the alignment test.