HP 995c Magenta, Brown and Black Print Only

[Bob Headrick]

Fair comment George, my understanding from the original post was that the two
cartridges had the same missing colours.....however we should never overlook
the possibility of two bad cartridges.

The first cartridge had been sitting for a year or more in an unused printer; I
would discount this failure as not entirely unexpected, depending on how the
printer was stored. As for the second cartridge, the two outer chambers (cyan
and yellow) are the most susceptible to shelf life storage issues.

If the original poster still has the original cartridge here is a test. (Do
not do this with a cartridge you care about, but let's assume that this
cartridge is bad at this point....) Soak the printhead head down in 1" or so
of warm water for 10 minutes or so. Take the cartridge out and let it dry.
Now try printing a self-test diagnostic test as shown at:
http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&cc=us&docname=bpd07098&dlc=en&lang=en#N10278
Use the diagnostic test - with the power on press and hold the power button,
then press the X button eight times rapidly (while still holding the power
button) then press the formfeed button four times rapidly, then release the
power button. At this point you should have nozzle patterns of weak (watery)
cyan and yellow and OK magenta. If this is the case get a fresh new cartridge
and your problem is solved.

If the problem were an electrical issue the printer would give an error message
about a defective cartridge as the printer does an electrical test of both
cartridges before a print job.

Regards,
Bob Headrick, not speaking for my employer HP

 

[Bob Headrick]

Have HP cartridges got suddenly less reliable then? Because this is
after two different cartridges? You mean to say that *both* are
damaged including the new one the OP specifically bought to see if it
was the printer or the cartridge?

No, the first cartridge was very old, and stored in an unused printer for a
year or more. It may have run out of ink before it was stored. The second
cartridge is not an HP cartridge and I cannot say anything about its status
(other than it appears to be DOA).

Electrically the cartridges (and the associated contacts, flex cable, head
drive ASIC, etc) are OK or the printer would provide an error. It does a
rather extensive electrical check of the cartridge at power-on and before
printing.

Regards,
Bob Headrick, not speaking for my employer HP

 

[Tony]

Even though this new cartridge is from a remanufacturer, the critical
issue seems to be how one goes about analysing where the problem might
be Clearly it could be at least one of these:

a)bad ink in cartridge:

unlikely given the blot test shows three colours.

b)bad contacts on the cartridge:

possible, but this is a second cartridge from a remanufactuer, so
possibly unlikely

c)bad contacts cartridge cage:

possible, but more likely the ribbon connector?

d)failure at the other end of cable:

possible, difficult to check without disassembly

e)flash corruption:

Unlikely either in file or RAM as CRC (I'm guessing) reported "flash
successful".

f)Other hardware failure:

but why do POST diagnostics not say so?

What's bad here is the absence of any internal diagnostics from HP that
say that the printer is not functioning as it should be The engineers
have clearly tried to anticipate what might go wrong in terms of a
POST, and the positions of the cartridge trays attempt to signal this
The POST says all is OK, but I reckon the printer should report that
something's wrong. It reports if the cartridges are short of ink! If
it's a RAM, or other hardware failure, which is responsible, I guess it
could have been overlooked. Still, there are ways of checking for RAM
failures - computers depend on this after all.

What we have here is the user knowing that something's wrong, but the
printer behaving as if there's nothing wrong. In my book, that's "bad
computing/engineering".

Thanks for everyone's thoughts. They have helped mine. Any further
suggestions obviouslly welcome.

Adrienne
Please read Bob Headrick's latest post. Well worth trying what he suggests.
All I can say about printers reporting failures or not is this - in my
experience HP printers of this age are pretty good at self diagnosis however it
has to be said that with the best will in the world it is almost impossible to
diagnose every conceivable failure without pricing equipment off the market.
There are other printer manufacturers that do a woeful job of diagnosis, Hp is
among the best especially their laserjets.
Tony
Tony

 

[Hecate]

No, the first cartridge was very old, and stored in an unused printer for a
year or more. It may have run out of ink before it was stored. The second
cartridge is not an HP cartridge and I cannot say anything about its status
(other than it appears to be DOA).

Electrically the cartridges (and the associated contacts, flex cable, head
drive ASIC, etc) are OK or the printer would provide an error. It does a
rather extensive electrical check of the cartridge at power-on and before
printing.

Agreed. However, we had one where it didn't report any error at all,
but refused to print magenta (or any combination thereof). This was
using all HP cartridges and with a couple of new ones as well (we
usually have a small stash as they're the general office printers -
and yes, they were 6 months in date <g>). Whilst it may have been
something repairable, it just wasn't worth the hassle. We just bought
a new printer.

--

Hecate - The Real One
(e-mail address removed)
Fashion: Buying things you don't need, with money
you don't have, to impress people you don't like...