Hello and welcome to the TSF. Best I could gather from the net, an e-90 error is a fatal error with the printer itself, the only solution is to contact Epson if the unit is still under warranty. Otherwise I understand the fix is more cosstly than the printer. The error seems to be reported most when a new black cart. is installed, you could try reseating the cart, powering down the unit for 15 min and then plugging back in and see if that will reset the printer. You can also try the SCC reset utility....
http://www.ssclg.com/download/sscserve.exe