If ink has been pulled through the head, either you can see it in the caps or the clear "Y" joints on the pump lines, and it is sill not printing 90% of the time it is a cable issue. You may have dislodged one while changing the damper.
If the cables are fine, did you turn off the power and remove the power cord before changing anything? ink on a powered surface of the head, or still wet ink when power is restored will fry the fuse(s) on the main board.