The ADEV might have stopped responding. Press and hold the POWER Button on the top of the ADEV for at least 12 seconds to turn the ADEV off, and then press the POWER Button again.
If the preceding steps do not turn the power on, the battery might not be sufficiently charged. Charge the ADEV as described in 5.1 Charging the ADEV.
If charging the ADEV does not resolve the issue, check the following.
Use the dedicated AC adapter for Switch (the HAC-002).
If there were no problems with these connections, disconnect the AC adapter from the power outlet, wait 10 seconds, and then reconnect it.
CONFIDENTIAL