My printer is a Deskjet f4400 and it stopped working today. I have read online that the problems I have are similar to other problems with HP Printers. When I try to print a test page or clean the print cartridges, there is a message that says 'out of memory' so nothing happens. Also, when I put only my black ink cartridge into the printer (I know it is in the correct slot and is clean) there is an error of some kind. It says 'electrical failed pen error.' Could this be because there is not much ink in the cartridge? Because I want to refill the cartridge, but if there is an error in the actual cartridge, then refilling it would be pointless, right? This morning I tried to print something and the paper did not feed, but now when I try to print something, the paper sometimes feeds, and it sounds like the cartridges are being used, but only a blank piece of paper comes out. I believe there is still ink in my colour cartridge, which does not have an error when I only put it into the printer. Any help would be great, thanks!!