HP DesignJet T1700 Print Head errors

[onihikage]

Hi, all. My first post on the site, so I hope I'm doing it right. This DesignJet T1700 problem is one I inherited from a more experienced coworker who was kind of scared of taking it apart (he has anxiety, part of why he left when the pandemic started hitting our town). I'm still quite new when it comes to repairing printers, and this plotter is an absolute unit, so I'm feeling a little out of my element.

This is the approximate sequence of events as I understand it:

1. Local staff replaced print heads
2. Printer presented some kind of print head error, coworker was dispatched
3. Print heads and ink were removed and the printer was power cycled to check for missing print head message (coworker's notes on the ticket don't mention results of this check)
4. Ink cartridges installed one at a time before the print heads were installed
5. Printer shows all three print heads are bad even though they are new
6. Coworker concludes the Carriage PCA needs replaced
7. Coworker leaves the company in fear of the pandemic, ticket is passed on to me
8. I go on site with the Carriage 3PCA w/TC44 service kit and a service manual PDF, having studied the replacement procedure beforehand
9. Carriage PCA is replaced, but the trailing cable is not (I misinterpreted the SM and couldn't remove a part that I thought needed removed)
10. The same print head errors are still present - viewing each print head through the display panel shows "Replacement incomplete, start again" or "Reseat required" depending on the print head and how many times I try to reseat them.

So that's where the previous service call ended. I'm ready to go back over there and swap out the trailing cable, but I can't shake the feeling that won't solve the issue, and there are other things about the situation that are bothering me.

First of all, the print heads weren't labeled properly when installed the first time, which I didn't know to check for until later (and my more experienced coworker apparently missed this entirely). Based on what the local staff described, the print heads were almost certainly swapped around even before I showed up, and will need replaced (again) anyway, even if swapping the trailing cable resolves the errors. As I understand it, each print head is configured for the color slot it's first inserted into, and putting it into another slot will mess up the colors. If it messes up anything else, that would be helpful to know as well. Is the printer smart enough to know the print heads are in the wrong place if they're swapped around after their first installation? Would that be causing the "Replacement incomplete, start again" error?

Secondly, the manual mentions the possibility of damaging the print heads by not inserting/removing them gently enough. How concerned do I need to be of that possibility? Would damaged print heads maybe explain the whole situation? They never went in quite as smoothly as the manual described. I'm also concerned about the ribbon cables with the little contacts on them that the print heads press against when installed in the carriage, and what I would expect to see if one or more of those cables was damaged when I was switching out the carriage PCA or from one of the others being too rough with it.

Thanks in advance for any assistance you folks can give me.

[Kiran Otter]

My apologies for not replying to this sooner, I simply missed the post.

The T1700 indeed uses universal printheads, which once inserted can not be moved to another slot/color. If you're uncertain about their status, the best thing to do in my opinion would be to start with a new set of printheads. Always rule out the consumables first.

The rest of what you described does sound like a bad carriage PCA, trailing cable, or possibly the electronics module. Replacing the carriage PCA and trailing cable first would be the best way to go. The printheads aren't any more or less fragile than in other Designjet printers. The most important thing is to remove or insert them by moving them directly up or down; don't roll or rock them front to back into the slot. The contacts in the carriage can be cleaned with water and a paper towel, or I use Simple Green. Just make sure it and the head are dry before putting them back in.

Generally the message that the printhead replacement wasn't complete indicates a problem with the printheads themselves. I haven't had too much experience with the universal heads but I can assume that swapping them around is a 'bad idea'. Start with new heads, label them so they don't get put in the wrong slots, and go from there.

Kiran

[Lance15]

Not sure if this is worth looking at?

HP DesignJet T1700 Z6 & Z9+ - Printhead rejection troubleshooting - Left-spittoon ink build-ups.pdf


I think I was working on a Z6xxx where it was doing the same thing. A firmware update addressed it.

As for the carriage flex cables. I had to replace them on, again, a Z6xxx for printhead rejection issues. I was VERY careful with those fragile FFC cables that attach to the carriage PCA. Was kinda nerve wracking. Not much room to push those cables into the connectors.