I turn off my printer when not using and the last time I turned it back on it had a "printhead error". It had been 3-4 weeks turned off. Sometimes the error is specific: "Oxc19a0002. There is a problem with the printhead". I know nothing happened to it b/c I didn't touch it and it was fine before I turned it off. I did some troubleshooting after checking the hp website but nothing has worked. Can someone help? Thanks in advance!