"if the cartridge is inserted and is 'full' of toner the printer assumes the cartridge is new and it resets the counter for the typical output" Exactly; I've d

"if the cartridge is inserted and is 'full' of toner the printer assumes the cartridge is new and it resets the counter for the typical output" Exactly; I've done the same trick with Brother toner cartridges for quite awhile now by using black electrician's tape. The sensor is just an optical fill check, there is no communication going on between between the toner cartridge and printer (although the cost of the official cartridge could make you think it's capable).