HP C4810A inkjet print head ID chip pinout?

[hanakp]

I know it's a long shot, but maybe someone will know: I'm trying to find some info about pinout and communication protocol on HP11 inkjet print heads, specifically on black variant C4810A. I'm not actually interested in the nozzle array, but about ID chip that stores serial number etc. It even has 4 separate pads on the pogo connector. We have old full-color powder 3D printer Zprinter 650 which uses 5 of these heads for color binders. But suddenly, the heads last only 25-40% of their expected life and then throw "head check error", meaning the printer is unable to communicate with the ID chip. It may be just a bad head batch (or they're counterfeit), but it also may be a problem within the printer (maybe overvoltage transients fry the chips?). I already throughly cleaned pogo contact board and replaced carriage flex cable, but the problem persists. Plus, each head costs about 60 EUR and I don't want to waste them needlessly. They're pretty well hidden inside the print carriage, so any info would make debugging much easier. I found several HP head pinouts online, but none of them has an ID chip:

https://spritesmods.com/?art=inker&page=2

https://ytec3d.com/hp45-inkjet-printhead/

https://sudonull.com/post/31720-Hacking-an-HP-color-cartridge-turning-it-into-a-handheld-printer

I also tried searching HP patents about it, but no luck.

[amyk]

Get a cheap logic analyser (the FX2LP "Saleae clones" will be sufficient) and examine the protocol. Beware that print heads may have higher voltages for the actual printing elements (e.g. Epson piezo heads have a 42V ramp signal.)