z3100 purge MK-R

[gfsymon]

Hi,

I've had some serious MK-R printhead problems, but amazingly have managed to apparently clear/clean the head with some help from an ex HP designjet engineer and notably, Mark Lindquist's 'memory' page.

I could have just replaced the head, which wasn't printing MK at all and R very pale.  However, simply letting it sit in 2 to 3mm of water overnight, some squeezing and shaking and some more soaking has completely cleared it.  So that's good.  However, I'm left with a Red (orange) which is printing pink.  The ex engineer tells me that I need to purge a lot of ink through to get rid of the 'bad' ink (the printer can sit unused for months on end).  The problem I have, is that purging, uses many feet of paper and purges many inks. Has anyone ever managed to purge only the MK-R (or any other head)?  Is it even possible on the z3100?

Thanks for any pointers.

[Mark Lindquist]

First, do several ( more) head cleanings. Do them consecutively on MK-R.
Then create a red square that will fit on either an 8x10 or larger sheet. Print that out.
Download the printhead excercise pattern on my website under manual cleaning printheads.
Print that out, then do a diagnostic print on gloss or semi-gloss paper and recheck your reds. It should be better by then. Forget trying to do a purge. Just force ink through the head and start printing with it. You have to pay the piper one way or another. Find an image that you have that has a lot of red in it and just print several the way you normally would. It shouldn't take long. If it is still printing funky you may be fooled by the printhead and need to get a new one. You can always do a blot test to check and see that it really is functioning correctly.

Good luck - Mark

Edit - if your printer has sat for a very long time, you'd be well served to pull all the cartridges and put them in sealable plastic bags and shake them vigorously - very thoroughly, then put them back in. BTW - the diagnostic chart is your friend with getting it back right.   It may not make sense but if you do a paper advance calibration that often helps.   I recommend getting a new printhead asap.  - M

[gfsymon]

I recommend getting a new printhead asap.  - M

Thanks Mark,

In the end, I've just taken your advice and ordered a new head directly from HP.

I had clearly managed to unblock it quite a bit, but I could see it taking up a few metres of paper and a lot of ink and in the end, I'd have a working 'old' head, if all went well.  The test print was showing lots of missing lines in the MK.  The Red was completely fine, with unbroken lines, but would perhaps take a LOT of printing to get the colour back correctly.  So the new printhead is perhaps a bit more expensive, but probably worth it.  The rest of the heads seem to be almost perfect.  I live in the Seine valley, so our humid, mild world is probably ideally suited to a z series printer sitting unused for months on end.

In terms of HP's print quality troubleshooting techniques, I wish I'd been through this when I was still (vaguely) involved in their photographer's program.  Really, there needs to be a way of printing a test sheet and then for the printer to *verify* that the colours are within the expected gamut limits of their inkset.  Being the first printer with a built-in spectro, it would seem that HP missed this trick.  The problem for me being, that I have an MK-R head which is printing R without any gaps in the diagnostic print, but with a very pink/pale red.  So if I go ahead and profile, it will be wildly out and then presumably will compensate thanks to the profile, but subsequent prints will become increasingly inaccurate as time goes by and presumably the red ink becomes more accurate.

So how do I know when the R is printing correctly?  No way of being sure I guess.

[Mark Lindquist]

Well, there are a few things going on with the Reds.  The fact that the R-MK printhead is acting funny is a big issue.  Another issue is that your cartridge could be funky.  Is it out of date?  Presumably it is if you've had the printer sitting for a  long time.  Another thing is that the red cartridge alone is not responsible for the red you see.  There are many combinations of inks that combine to create red.  When you get the new printhead I would still take the cartridges out and shake the heck out of them.  Even with a new printhead, you'll need to do a head cleaning first in my opinion, then print out the diagnostic chart again.  I recommend using a magnifying glass and really going over it with a fine tooth comb.

If after doing this stuff, take it for a test spin and print some known images and see how it compares.

Really, anyone serious about using these printers should have a diagnostic chart saved from when the printer was new to be able to compare to.

Presumably you have save the most recent diagnostic charts.  After you've replaced the printhead and done a printhead cleaning and printed a new diagnostic chart - just compare them.  Look at the solid colors and compare.  You should see a marked difference.

If not you have something else going on likely with other printheads or cartridges.

These printers are meant to be left running 24/7/365 so the micro drop technology can work its magic.  If you've left it sitting with it being off, then you may have to grunt through some extra printing to get it to come back.  I also advocate doing some print exercises now and then, not just leaving it for several months unless you have to.  I've left mine for 2-1/2 to 3 months before, unattended, plugged into a UPS, when I was on an extended shoot and when I came back I had to futz with one of the printers, but the others were fine.

I have a feeling you'll be ok and it will come back after a little love and some exercise.

-Mark