I had the same issue - after turning on, the printer doesn't warm up - just shows status OK and none of the buttons doesn't anything. 2 day's couldn't figure what's wrong with it!
but, today decided to plug in LAN cable (previously i was using only WiFi) an unplugging/pluging-in powe cable, i heard a click and printer came to life!
Don't know what it was, but now it's working... hope it helps!