unknown

asked Oct 3, 2011 at 2:13am
Hp HP Color LaserJet 2840

HP Color LaserJet 2840 bypass replace cartridge?

I just picked a '2840 up off the side of the road, of all places...!

The only thing that seems to be wrong with it at this point is that it's complaining of an empty black cartridge.

Since I don't know if there's anything else wrong with it I don't really want to invest $50 in a new cartridge just to find out the printer had some other issue, so is there any way I can bypass the "replace cartridge" brick wall? Some kind of hold these-7-buttons-down-at-once-then-press-this-one-for-2-seconds trick? :P I can touch my finger to the black cartridge and ink comes off on my finger... I'm 100\% sure it has enough left in it for at LEAST a test print.

Thanks a heap!

-i336
Those cartridges have a smart chip. Buy one black chip off ebay or a local re-manufacturer (if you can find one) and replace the chip only. That way you are not out much in case of other problems on the machine.
by unknown on Oct 3, 2011 at 7:33am Add comment
*sigh*

Life's been a bit hectic at the moment, so I haven't been able to get back here...

I actually figured as much out. I kinda realized... hang on a minute, that chip ISN'T wired to the cartridge and isn't a make-ink-come-out-now-kthx trigger point of some kind, it's an ID type thing!

So I actually got a bit of a brainwave, and using an advanced combination of sticky tape, foil, and wire, successfully (!!) re-wired the cyan cartridge such that its contacts were presented when the carousel rotated to the black cartridge.

Guess what? It worked!

...well...

Printer: "Wrong Black"

D: D: D:

Now all we have to do is find someone who's reverse-engineered the little communications protocol the chip uses, and get them to make a guerilla chip that reports the color you want via maybe a switch, and always report 3000/4000 days of lifetime left :P Haha... we can dream, can't we? :P

Back to reality, thanks for the advice about getting the appropriate ID chip. This shall be duly considered.

-i336
by unknown on Oct 9, 2011 at 9:23pm Add comment