Nicholas Bodley wrote:
Got me baffled. I partially-disassembled a used Epson cart. for an
RX-580, and what I found made little sense. Also curious how "chip
resetters" work.

Sorry if this has been recently answered. [inkjet cartridge] at the
Repair FAQ came up null.

Most of them don't. They store the ink level in the chip (100%). As the ink
gets used, the computer updates the chip with the amount left by subtracting
about what it thinks was used.

There have been all sorts of software mechanisms (and lawsuits about them) to
prevent someone from updating the chip to reflect filling the ink well.

HP used a different mechanism, I don't know what they use now. They had a
chip permanently programed with the serial number of the cartridge and
the printer kept track of them. It could only hold 3 in memory, so if you
had 4 cartridges, or used tape to change the reading of the serial number
(blocking contacts), you could reset it.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM