When the Nintendo Switch is completely dead, the screen will remain black and there will be no indication that it is charging. However, you can check if the console is charging by plugging it into the charger and observing the orange LED light on the console. If the light is on, it means that the console is charging. Once the battery has charged for a few minutes, the Switch should have enough power to turn on and display the charging icon on the screen. However, if the battery is completely dead and there's no light indicating that it's charging, leave it plugged it for at least 1 hour and check it again after that.