Appreciating the urgency, I will offer what is perhaps not terribly helpful. It really sounds as if your cartridge(s) has/have become partially clogged, probably due to having been unused for extended periods whereby some of the ink has dried out and left a blob of pigment large enough to impair the function. I have experienced something similar in the past and, having stubbornly tried to clean, dissolve, etc. using both water and pure alcohol, had to give up and replace the cartridge. It is also possible that there is a contact or conductor fault (see tiny copper-like traces on the tape-like band which probably is visible on one side of each cartridge) leading to a "blind/blank" trail being left because the jet does not fire when it is supposed to. I recommend you install a fresh cartridge if you are in a hurry to do some printing where a flaw is unacceptable. If the problem persists then it is almost certainly more serious than just to do with a cartridge. Meanwhile I shall watch to see if anyone can suggest a very effective way of unclogging cartridges.