Blowing will solve nothing because there is a sensor inside the printing head and it is covered with ink not with paper. i had the same problem with my unit. By the way, it is very easy to reach to that sensor.you have to dismantle the unit so you can reach to printing head, then all you have todo is wipe with alcohol that sensor. e-mail me if you want me to give you step by step instruction.
ps: excuse my english (it is not my native language)