It's my wife who has the X73,we found that removing the electric and USB cables and reconnecting same cures some faults. If that doesn't do any good you could try above and also remove printer software and reinstall printer as per manufactures instructions. Sorry I can't suggest anything else but now this thread will be bumpted up where someone else may be able to help you.
Try standing the cartridge on a damp paper tissue and see if you get any ink flow at all soaking into the tissue. If you do, it's a printer problem. If you don't, it's a cartridge problem. See how you go.