IIRC, DMCA exempts reverse engineering to create competing products, so I think this thread is legally safe. But feel free to remove this thread if it has potential legal hazards to Vogons.

So I purchased HP Deskjet D2566 few months ago. At first, I'm happy with its printing speed and the inclusion of power button.

I, of course, use refills, since HP genuine cartridge doesn't add any value to me as consumer whatsoever IMO (not to mention genuine cartridge runs out of ink pretty quickly). Void warranty be damned, I have used refills on various printers, and in contrary to what HP claims, refills don't damage printers. At least on my experience.

However, a particular strange things happen when I start using refill on the D2566. The print result is highly blotched, giving the impression of damaged print head. However, I also noticed two strange things:
(1) The blotches are suspiciously regular. In fact, they are way too regular, almost like deliberate.
(2) Getting suspicious, I quickly rushed to a friend who happens to own a D2566. His printer, of course, has never used my refilled cartridge before. When I put the cartridge on his D2566, everything prints smoothly, without the blotches.

Thus, I suspect HP has put some nasty DRM on its printers to recognize a cartridge that has been previously used (probably using cartridge serial number or such). But I also read you can "reset" the printer battery to erase your cartridge serial number. Alas, I'm totally unfamiliar with D2566. Has anyone been successful in resetting their D2566?

Thanks,
-Kresh