2024-12-31 - Replacing the Printhead on an HP OfficeJet Pro 6960
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I've had an HP OfficeJet Pro 6960 lying around for a while that kept
having issues with the printhead being clogged[0] (I got it for free
because of those issues). I fixed it a few times already by opening
the top cover[1] and squirting isopropyl alcohol through the print
head. The way I did this was by opening the cover while the printer was
on (so the printhead with the cartridges would move to the center),
then unplugging the printer. If the printer isn't unplugged, the
printhead will eventually move back to the side, so it's safer to
unplug it completely. I then placed a paper towel underneath the
printhead and squirted alcohol through the printhead from the top where
the cartridges are usually located[2]. This sort of worked a few times,
although I'm not sure if there are maybe better cleaning fluids than
isopropyl alcohol, maybe even just distilled water. There are special
kits for unclogging printheads which include various rubber tubes
and special cleaning fluids, but I didn't have one at the time.

This time, however, I couldn't get it working anymore, no matter how
much I tried. One color simply wouldn't print, no matter how much I
tried to clean the printhead. The main problem was that I was somewhat
stupid during my previous repairs since I didn't have the proper
equipment. I only had a plastic syringe which I pressed fairly hard on
the ink intake, eventually compressing the porous material too much[3]
(the rubber part in the picture was just removed in order to clean
away some excess alcohol that I spilled beside the ink intake). If
I had gotten the proper equipment (really just some rubber tubes) in
the beginning, I probably wouldn't have had this issue. Also, it might
have still been possible to unclog the head by completely soaking the
ink intake in distilled water, but I didn't think of that at the time.

At this point, I was faced with a tough decision. Should I throw the
printer away, or should I buy a replacement printhead for more money
than a used but working printer of this type can be bought for? The
answer was obvious. I bought a replacement (used) printhead.

Disassembly
-----------

In order to replace the printhead, the plastic cover obstructing it
needs to be removed. In order to get to all the screws, the plastic
connector holding the scanner assembly needs to be disconnected,
which can be done by using a screwdriver to push it out[4]. The
credit for this trick goes to [5], which also helped alleviate my
fears about using too much brute force during this step. It is best
to lean the scanner assembly against something to stabilize it since
it isn't held by the plastic connector anymore.

All the screws around the edge can then be removed[6]. In order to
remove the cover, the display at the front needs to be disconnected,
which is a bit annoying. It is held on by a lot of clips on all
sides, so it takes a lot of messing around until it finally comes
off[7][8]. There is also a ribbon cable that can be disconnected
afterwards[9]. Once the display is gone, the cover can be removed,
but another ribbon cable has to be unplugged in the process[10][11].

Printhead Replacement
---------------------

The printhead is held by two strong springs[12] that need to be removed
before the printhead can be removed[13]. There are also three ribbon
cables on the printhead that need to be unplugged[14] before it can
finally be removed[15]. There is a plastic timing strip that is in the
way when taking out the printhead. It is probably better to remove
that completely since it is only held by hooks at the sides of the
printer[16], but it was possible to carefully remove the printhead
while the timing strip was still in place. Putting the new printhead in
place is really just the same procedure, but backwards. One important
thing to watch out for is that the timing strip goes through the sensor
on the printhead.

The ink intakes on the new printhead do look like they're in a much
better condition than the ones on the old head[17].

Reassembly and Testing
----------------------

While I had the printer open, I decided to clean up some of the
waste ink on the right side[18], but it wasn't really possible to
properly clean it up. I just cleaned up the worst part of the sludge
and then decided to leave it as is. The rest of the reassembly is
fairly straightforward, although it might take a bit of fiddling
around until the cover clicks into place around the hinges for the
scanner assembly[19]. The connector on the right-hand side can just
be pushed in again with a bit of force[20].

When I tried printing, I first thought that the new printhead was
also clogged because black wasn't being printed. I even tried to
unclog the intake for the black ink, but nothing worked. Luckily, I
had another black ink cartridge lying around, so I tried that after
all else failed. To my surprise, everything worked perfectly with the
new cartridge. I have no idea why that was because the old cartridge
definitely had a lot of ink left and was working perfectly with the
old printhead (cyan was the color that wasn't working before).

Conclusion
----------

Perhaps this whole ordeal was unnecessary, and it would have been
possible to unclog the old printhead. Still, there might have been
more issues down the line after the amount of damage I already did
to the ink intakes, so the replacement was probably a good idea in
the long run (especially because I am planning to give the printer
away to someone who probably wouldn't know how to unclog it).

Of course, this really didn't make any sense financially, but I just
couldn't help it. At least one less printer ended up in the trash
this way.

Actual Conclusion
-----------------

Inkjet printers are evil and should be outlawed.


[0] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printer.jpg
[1] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printer_open.jpg
[2] gopher://lumidify.org/I/phlog/2024-12-31-printhead/paper_towel.jpg
[3] gopher://lumidify.org/I/phlog/2024-12-31-printhead/bad_printhead.jpg
[4] gopher://lumidify.org/I/phlog/2024-12-31-printhead/top_connector.jpg
[5] https://youtube.com/watch?v=Ao-_iasByZ8
[6] gopher://lumidify.org/I/phlog/2024-12-31-printhead/screws.jpg
[7] gopher://lumidify.org/I/phlog/2024-12-31-printhead/display1.jpg
[8] gopher://lumidify.org/I/phlog/2024-12-31-printhead/display2.jpg
[9] gopher://lumidify.org/I/phlog/2024-12-31-printhead/display3.jpg
[10] gopher://lumidify.org/I/phlog/2024-12-31-printhead/cover_ribbon.jpg
[11] gopher://lumidify.org/I/phlog/2024-12-31-printhead/inside.jpg
[12] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printhead_springs.jpg
[13] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printhead_spring_removal.jpg
[14] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printhead_ribbon_cables.jpg
[15] gopher://lumidify.org/I/phlog/2024-12-31-printhead/printhead_removal.jpg
[16] gopher://lumidify.org/I/phlog/2024-12-31-printhead/timing_strip.jpg
[17] gopher://lumidify.org/I/phlog/2024-12-31-printhead/new_printhead.jpg
[18] gopher://lumidify.org/I/phlog/2024-12-31-printhead/waste_ink.jpg
[19] gopher://lumidify.org/I/phlog/2024-12-31-printhead/cover_reassembly.jpg
[20] gopher://lumidify.org/I/phlog/2024-12-31-printhead/top_connector_reassembly.jpg

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