In most cases, it's a waste ink pad full problem (the sponge that sucks wasted ink is full). But it probably isn't full yet (Epson claims it's full long before it really is!).
You'll have to download the service program for Epson printers (which gives you access to service functions of your printer):
http://www.eserviceinfo.com/downloadsm/22895/SEIKO%20EPSON_EPSON%20RX420-425-430.html
Run the exe file (it doesn't work in Windows Vista or 7 - you'll need old xp for that). Then Select Sequential Adjustment Mode. Select your printer model and then Waste ink pad replacement. Press Ok.
You might have to try a bit.
After you suceed, you need to turn off the printer and turn it on again. If all went well, you won't be seeing all the blinking lights on your printer ;)
www.cool-proxy.net
May 2010