A few questions:
1. Which paper are you using?
2. Are you sure you have removed all the blue packing tape? There should be around 50 pieces. Look carefully around inside, with a flashlight if necessary.
If you are sure you have removed all of the tape, and you're using, say, Epson Premium Luster for your testing, I'd suggest just calling Epson Support. Sounds like something is mechanically awry.