Yes this sort of thing is often never explained. It does explain why some
people find working devices in recycling centres, I'm sure.
Not enough time spent in diagnosis.
Brian

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From the Sofa of Brian Gaff Reply address is active
"Arfa Daily" wrote in message
...
For a long time, my primary printer has been an HP Photosmart series
all-in-one. It's a 6 ink job, which makes it expensive to replace inks if
you use the genuine HP article. So, for several years, I have been using
cheapo eBay inks. They come from China originally, and the most recent
ones I have been using, have translucent cases so you can even see how
much ink is actually in them. They are high capacity cartridges, and the
chip on them says so correctly. I have never had a problem with the
printer failing to recognise them as a high capacity cartridge of the
correct colour, and the usage indicator seems to remain accurate.

So, a couple of weeks ago, I come down in the morning, and it's sitting
there saying "copy abandoned", and the exclamation mark LED is flashing.
Sure enough, one of the missus's documents is in the top that she's
obviously been trying to copy before going to work. So I try the cancel
button - nothing. Nor the on / off button. No buttons work, so I pop the
power, just expecting to get the usual lashing for not turning it off
properly. But no. As soon as it gets going, it tells me that "The
following ink cartridges appear to be missing... " That would be all six
of them, then ...

Nothing would recover it from this. I had a trawl around on the net, and
there was a number of mentions of a couple of caps that bulge on the main
board, so I dived in to check, and yes ! there was one of them. I checked
its ESR for sport, and it was out the window. I stuck a new one in,
expecting all to be well, but it was just the same :-(

A friend lent me a printer in the meantime, while I had a think about this
one. Another friend is a pro photographer, and he has one of these HPs
also, and I knew that he only used genuine inks, so I rang him and asked
if he happened to have any empties laying about. He did, as he takes them
back to Staples, who give you half off in exchange. He came over today
with a bag of them, so I started by taking all of my cartridges out. As
expected, it told me that all of the cartridges were missing, so I put in
an empty colour one and restarted it. This time, it told me that only five
were missing, and the one that I had just put in was nearly empty and
should be replaced soon.

One by one, I added 'empty' genuine cartridges, and each time, it read the
cartridge ok. I eventually got to a full house, and all was well. So one
by one, I put my cheapo cartridges back in, and all remained ok, until the
very last one, dark magenta, when back came the message that all six
cartridges were missing. I went and got another from my stock and put it
in, and all was still ok.

So I'm guessing that the comms to these cartridges are just a simple 2
wire bus, and each colour just has its own address to allow the processor
to read them individually. I'm also guessing that the faulty dark magenta
cartridge, must have a short on one of the bus lines so that when the
processor issues the addresses in sequence to read each cartridge at boot
up, none of them are able to reply so the machine assumes that they are
not present.

How easy it would have been for the printer to have just got chucked in
the bin, for what was ultimately a simple problem ...

Arfa