Check the power settings:

1. Check the power settings of the computer to make sure it is set to automatically wake up from sleep mode.
2. Update the power settings to ensure they are configured correctly.
3. Check the external components (mouse/keyboard/monitor etc.) and make sure they are connected properly.
4. If the issue persists, the power cable of the computer may need to be disconnected and reconnected to a different power outlet.
5. If the above steps don’t resolve the issue, the computer may have to be restarted.