Eexpiry dates on HP Deskjet 920c colour cartridges.

[Rosalie]

This is about expiry dates on HP Deskjet 920c colour cartridges.

I'm looking for answers on these specific points :

1.Is the "Install By" date hardcoded into a chip on the cartridge ?
2. Does the PC keep a log of cartridges that I install ?
3. If so, is it in the registry, in a file ...?
4. If so, can the info be modified, deleted ? Worked around ?

I'm not into chemistry but I'm pretty doubtful that ink in a cartridge (in
an airtight bag, in a dark, cool, dry place) can switch from OK to useless
over a 9 month period.
I can imagine that it might deteriorate in such a way as to be
slightly less than perfect, but for one colour, cyan, in the cartridge to
just die
after a certain date would appear to be deliberate rather than due to
natural causes.

So, would annyone have any hard facts on that ?
TIA

Alf

 

[Andrew Rossmann]

This is about expiry dates on HP Deskjet 920c colour cartridges.

I'm looking for answers on these specific points :

1.Is the "Install By" date hardcoded into a chip on the cartridge ?
2. Does the PC keep a log of cartridges that I install ?
3. If so, is it in the registry, in a file ...?
4. If so, can the info be modified, deleted ? Worked around ?

I'm not into chemistry but I'm pretty doubtful that ink in a cartridge (in
an airtight bag, in a dark, cool, dry place) can switch from OK to useless
over a 9 month period.
I can imagine that it might deteriorate in such a way as to be
slightly less than perfect, but for one colour, cyan, in the cartridge to
just die
after a certain date would appear to be deliberate rather than due to
natural causes.

So, would annyone have any hard facts on that ?

There is no date coded into the cartridge. There is no 'chip' in the
cartridge. Each cartridge does have a unique ID code, but that is done by
cutting/connecting various traces on some of the contacts.

The printer itself remembers the current and previous cartridge ID of
each type. This is used to keep track of ink usage. If you rotate between
3 cartridges, you can use refilled ones and the printer will have no idea.
Even without that, the printer will simply keep thinking it's an empty
cartridge. Unlike Epson printers, HP printers will keep printing even if
they think the cartridge is empty.

The expiration date has more to do with warranty than anything else. If
you use an expired cartridge and have problems, you are on your own. HP
won't replace it for free.