Sorry for being unclear.
In the Black Ink change provided by epson, not the manual one that you linked, I was at the point where the printer asks to remove the CMY black ink conversion kit and PK cartridge and insert real CMY and the new MK cartridge. I did so, and when I put the lever in the lock position, a cartridge error message appeared on the printer.
To run a new black ink change, even manual, would not work because the low ink warning light is on.
Also, I checked the wires on chip sensor and they are in good shape and position, even compared it with others to be sure.