I bought an HP 6110xi for $10. Sign said, "just needs ink." Hooked it up but it couldn't finish its self-tests. I could hear the scanner element repeatedly bumping against something as it tried to move out of its bay. After a few minutes of slamming itself, it reported, "scanner failure, turn off and turn on" or something like that. I tried everything, eventually resorting to vigorous but measured impacts from various directions before I kicked it to the curb. These were not light blows. It still wouldn't boot but a new error message appeared: lid not closed (where you change the ink cartriges). Yes, the lid was closed. I slammed it closed again and again, not at all afraid I would break it. Suddenly, the led said,"push OK to align the ink cartridges." The machine has worked perfectly ever since. The lid or some part of it might have been blocking the scanner element.