Is it plugged into an active electrical socket? Sometimes there is a switch on the wall that turns the electric socket of/off. Make sure that switch is turned on.
Does the charger have a good connection? Some RSD Chromebooks have a spot on each side that you can charge from. If you have a Chromebook with that option and one side is not charging, try the other side.
Does it have a green light but won’t turn on? Do a hard re-start. Hold the power button and the refresh key for about a minute. The refresh key on a Chromebook is in the upper left-hand corner of the keyboard and looks like a circle with an arrow at the end of it. Let go of the button and if the Chromebook comes back on with a large exclamation point, press the power button to restart it.
Is there a red light on while it is plugged in and charging? If there is no light, the battery is completely drained. When that happens, the Chromebook will not turn on, even if it is charging. Let it charge in an active electrical outlet for 15 minutes.
If no light appears you may have other issues. Please submit a Help Desk Ticket.