Have you changed your firmware recently? Sometimes if you change the firmware with the cartridges in the machine, it makes it so that the machine rejects the cards. Normally all 4 cartridge readers don't fail all at the same time especially if you have changed the junction board. You should buy a new cartridge and see if that reads correctly. If it does, the cards are just bad and you should contact your ink supplier to see if they can get you new ones.