If you are coming across the offline issue and why does my HP printer keep going offline, here are the causes provided to you. This may happen if you have a printer that is either off or in sleep mode. A solution may be found for the problem, though. Certain parts of the printer need to be repaired in order to solve the issue. Start by checking the power line connection as soon as possible. After a few minutes, turn off the printer and computer and reconnect.