The LaserJet 400 m401n printer we have incessently says to load paper. I have power cycled by pulling the power cable, factory reset, cleared the queue, reset the paper in the tray, and realigned the paper in the tray. Not sure what else to do but the Load Paper message will not go away. I cannot print a configuration page from the printer itself, because it just shows Load Paper.
I had same issue was about to trash the darn thing and I tried one more time looking at the tray. Luckily I had another 401 printer. I sawpped trays and the error went away. The paper size indicator was one small (very small) "click" away from letter size on the "broken" tray. I moved the indicator to "LTR" and made sure it clicked in place. I put the tray back in and the printer works now!