DesignJet Z9+ PSA and a question

[Lance15]

Anyone who has worked on HP (don't know about other brands) plotters knows how "reliable" printheads are. Even when new out of the box.

Looked at this plotter a few weeks ago and found the M/Y printhead was faulty. I was told by the user they had already replaced printheads (I only found 2 open/used printheads).

Thankfully this customer is very understanding about my explanation of HP printheads and ordered a whole new set.

I went back today and replaced the M/Y printhead that I knew was faulty.

During the replacement process, it found two more, new, still under warranty (2025) faulty printheads. I replaced them when asked.

Finally, AFTER AN HOUR (no exaggeration), the plotter came back to the home screen.


PSA: Stick to your guns when it comes to printhead rejections, "printhead replacement incomplete", image defects, etc. Like many of us have said many times in the past, "rule out supplies first".

Question: Is the service print supposed to look like this? ONLY the service print looks like this. Everything else is perfectly fine. Just looking for any ideas. Don't care about fixing it.


Thanks!!

[Kiran Otter]

The internal prints shouldn't look like that. My first thought would be it needs a ph alignment but you've obviously been through that. The reason you don't see it in other prints may be because the service print is printed bi-directionally, and the rest of what you're printing is uni-directionally. A dirty or damaged encoder strip can also contribute to that ghosting effect. Or doing an alignment on exotic media.

What you described about the printheads would lead me to suspect something else, like air in the ink tubes. But if it finally came ready (and yes it takes forever!) and it's printing well, then good. The printheads have a warranty; send them back to wherever they bought them (not HP, unless purchased from HP.)

The biggest problem with the Z9 I've seen is the ink in the service station builds up and gets into the motor that moves the wipers. If you need a service station, get the PMK2; it's less expensive and has a couple more items along with the service station.

Kiran

[Lance15]

Thanks Kiran. I removed the Photo Satin they had loaded and loaded plain Bond just to make sure the printhead replacement would be successful. The manual said to NOT use semi-transparent or transparent media to align the printheads (duh....LOL). The Satin would have probably been fine(?), but, I know bond would work 100%.

Okay, that makes sense. Bi-directional vs. uni-directional. Will always get better results with uni-directional.

Thanks for the explanation and future repair possibility ?

[Kiran Otter]

Photo gloss or satin is OK if it's 'instant dry', otherwise just bond media is usually best.

Kiran