To solve the HP Officejet Pro 8710 Offline problem, the HP Officejet 8710 printer must be turned off. Thereafter, you must wait for roughly 10 to 15 seconds. Turn down your computer as well as the printer's power source, and unplug the printer from the wall. Further, reconnect the printer's power cable & turn it on after a short while. Afterward, if your printer is already connected to a wireless network, restart the router. Turn on the computer at last.