I have the esp c310 and it looks like it is printing but no ink. I tried different cartridges but the problem remained the same. So I dug deeper, this time I removed the printhead and cleaned it by soaking it in alcohol, this method didn't work. So I researched more and found a better cleaning method.
The next thing I did was to take a sheet of paper towel, soaked it really good and put it in microwave for 30 seconds till it was HOT. I put the printhead over the hot paper towel until paper towel cooled, and noticed ink coming out of printhead, did this several times until no more ink.
Tested it and Voila it worked now printer printing again.