For over a week now, I have been fighting a stubborn clog in the magenta channel of my Epson 7900, with no success. Over the years, each time I had some clogs, no matter whether they were stubborn or not, with each cleaning things would slightly and progressively improve till all was back to normal. This time, cleaning often makes things worse, in the sense that when I think I have gained back almost all nozzles a further cleaning makes me loose rather than gain nozzles... Here is some background info, hoping some of you might have experienced (and solved) something similar.
It all started with one quarter of the magenta nozzles not firing. Till now I have run several runs (over the course of several days and each interspersed with a couple of nozzle checks and sometimes a print) of CL1 and CL2 cleanings, and one run of CL3. Every time I waited 12 hours to confirm the results as it seemed to help (cleared nozzles would always be more after rest).
CL1 seemed not to help, CL2 made the situation better but each time I performed a CL1 after a CL2 things would be worse rather than better?! At one point yesterday after waiting for 12 hours after a CL2, all nozzles got back up but one! I was ecstatic! I "stupidly" performed a CL1 to get rid of that last nozzle (as I would usually do) and I lost "all" nozzles. Then I performed another CL2 and my first CL3 and have gotten back to having 1/4 nozzles missing. The fact that all nozzles (but one) came back momentarily might mean that the head is not fried (I hope). Interestingly, the nozzle pattern that I get after a cleaning procedure stays consistent after rest or printing (next day would look the same if no cleaning were performed, and the same would happen after a couple of 8x10 pages of magenta). Any thought?
By the way, is there any correlation between Epson "Power Clean" and CL3/CL4 in service mode?
I wanted to do a power cleaning as I have read that It might help in case of air bubbles (in case that's the problem), but can only see the option in the standard menu, which I don't usually use. I think that it's strange that the service mode would not have the "power clean" option so perhaps Cl3 or CL4 are the code names for Power clean? Scouring the web I found a reference to CL4 may be being like a "pair init-fill", but it wasn't conclusive so I'm not sure.