We both agree this sounds like one of two things, either there is air present in the lines OR you need to perform a cleaning on the Capping Station, Wiper blade and bottom of the Print Head.
To check for air in the line(s) simply inspect the lines running from the cartridges to the print head carriage assembly to visually look for air bubbles or lack of ink.
Perform a cleaning on the recommended parts above, follow this link http://www.inkjetmall.com/tech/content.php?133-Printer-Cleaning-and-Preventative-Maintenance Doing this procedure will NOT harm your printer in any way, and should be performed once every 6 months or so depending on use.
If there is NO air present in the lines and performing the recommended cleaning, it could be a clogged damper (dampers should be replaced as recommended by Epson, once a year). Worse case scenario, the head has failed, which for your sake I hope is not the case.
Please let me know your findings after you inspect for air in the line(s) & have preformed a through cleaning.