I have developed the same problem on my HL-2380DW. Try unplugging the machine from the outlet for at least a minute and plugging it back in. If it turns on after plugging it back in I am thinking it could be a bad capacitor in the LVPS. Don’t have access to an o-scope so I am checking on finding a new power supply board. Using a multimeter probably won’t do much good without a schematic.