why does my hp laserjet 4250n lights stay on?

why does my hp laserjet 4250n lights stay on?

please be more specific on this, is these a brand alien machine, if yes you better christen for service maintenance it is free or stili below warrany, if not what is the error code flashing on the lcd display, be more speficic, hp4250n is a complicated device, prom dress rental