Maybe replacing them all would be the way to go, after you try and revive them. Particularly see how the ink is in the lines. If at all dried up, you maybe ruining new print heads.
My MK print head was brand new, and in 2 weeks time from obtaining the printer I had a clog, and still do. I will be using a couple of the methods from Marks post to clear it before I replace it.
I had thought of ultrasonic cleaner, and glad someone else was thinking along those lines. The video and the other thread are great help.
I don't see mention of which solution for Epson is recommended. Is there a model or part#, or link?
One thing I want to clarify, and I might be able to do that by asking ...
If you select Replace Print head on the printer options in ImageQuality, will a paper you use need recalibration? I would think it doesn't, but does the internal process force this?
Also, what is a good way to have the carriage move into position for print head removal without forcing any actions?