"1.)If you press the on and cancel button for a few seconds at the same time the printer will start again correctly
2.)unplugging it, holding #6 for few seconds (may be 10 to 15 secs)
3.)press the ON along with OK both for few seconds
4.)press the on and cancel button for a few seconds at the same time now.
or if it is a wireless printer you can do this
then there is most likely a problem with the wi-fi card. Removing the back and disconnecting the wire harness to the card should restore functionality if not there must be a hardware problem please take it to a service center"