I'm having this problem now for a few weeks. My printer, P600 will not recognise any cartridges. I have changed the ink bay, the printhead, the motherboard, front panel, head cables, pretty much everything I can think of connected but still have the problem,I don't understand it. I've tried different sets of carts including the original epson but still the same. If anyone could shed some light on this, would be much appreciated.