Hello everyone
I have an Epson PX730WD that has the same problem.
I have seen that no one could solve the problem, but he liked to take some doubts.
1. When did the head cleaning removed the print head?
2. The head was dipped in a liquid for cleaning?
3, hung up the tape printer head connection?
I think the problem is not in ink cartridges but the print head.
I do not know if you have entered some liquid to the electronics of the printer head that causes this.
Or otherwise the ink does not flow to the head as it should and causes this error, I read somewhere that when one cartridge ink error from time to time, it should be to lack of ink, ie the ink does not flow in sufficient quantity and the error as if it were empty.
Forgive me my English not being the best and hope that I can understand.
Thanks
José Rodrigues