У меня вот это загуглилось: (правда подробно не гуглил)
1. Turn off printer.
2. retaining button Resume/Cancel press button POWER - indicator it will catch fire by green color.
3. let go button Resume/Cancel, continuing to retain POWER.
4. press button Resume/Cancel of 2 times, retaining POWER, after which let go all buttons.
5. when indicator will be lit BY GREEN - press button Resume/Cancel of 4 times.
6. turn off printer by button POWER. Power on later, that should fix the problem.