I have owned the EN980e for years and no probelms. Recently the screen will go "blank" for no apparent reason. The computer acts as if nothing is wrong ( No error report, not in sleep/hibernation). The monitor light stays green ( not in power save mode). The screen is black mostly with ripples of white light. Pressing panel buttons has no effect. Is there a combination or sequence of buttons to press to force monitor to factory default? Manual does not specify.