I have an Epson CX3600 all i one Scanner /Printer.
I had'nt used it for a while and just reinstalled it.
Problem is only the Blue is printing and not the Yellow'Magenta or Black Cartridges.
I replaced all 4 cartridges with brand new ones and still the same.
I've done repeated cleans and nozzle checks and they all are still the same.
Called Epson who pretty much told me to not bother them as i am not using Epson cartridges'but the cartridges i'm using are fine and i've used them before.
Print heads are probably clogged. If your printer was not used for some time, the ink probably dried in the nozzles, and the printer head cleaner isn't enough to clean them out. Easiest thing is to try a third party head cleaner for your model of Epson. Search the web. If your really knwo what you're doing, you could try to clean them manually with some isopropyl alcohol. Take out your cartridges and place about 8-10 drops of alcohol down the little hole where the ink flows from the cartridges into the printer. Reseat the cartridges and run the head cleaner. It may take several tries to clean them out, and you may have to let the alcohol sit in the nozzle for awhile to soak. Remeber, the head cleaning uses a lot of ink, so if you do this a number of times your likely to use up a cartridge. Try not let the printer sit idle for so long.