unblock yellow cartridge print head?

I experienced the same problem but I have an Epsom R 300 which has been discontinued. All I did was remove the yellow cartrige, block the openning on the cartridge with my finger, shake it about a few times and re-inserted it. I will not bore you with the details but is is all about primary and secondary colours so after it went through the cleaning cycle, I just kick-started the sensor by creating a small spread sheet in excel with just two colours, red and yellow. This printed and have had no problem since. Hope this simple idea works for you.

Emma
June 2010