A "on/off" behavior usually indicates that there are hardware problems with the printer. You will have to check or replace the cable in the first place. Make sure the USB cable is attached properly to a PC if you use one and the AC cord is properly connected and plugged in the socket. If you still encounter issues, re-install the printer using its Support CD. Additionally, press the POWER button for 10-20 seconds. If there is an error with the memory, this procedure will clear it.
From another point of view, the printer might require service repair because of the faulty components or hardware.