Welcome to the Support Communities! The article below will help you troubleshoot the issue you are having with your Macbook Air not waking from sleep:
If you are using a Mac notebook:
- Make sure the computer's battery is charged. Try connecting the power adapter to the computer, then press the power button for one second to see if the computer powers on.
- Make sure the AC power cord is connected securely to the power outlet, and that the outlet it is working correctly. Confirm the power adapter or cable is attached firmly.
- If your computer is plugged into a power strip, make sure the power strip is not turned off. Check to make sure other items connected to the power strip are receiving power.
- Confirm the right power adapter is connected on Mac notebook computers. If a lower wattage power adapter is used than the one that came with your Mac, it may not provide enough power to charge the battery while the computer is powered on. Make sure there is no debris in the MagSafe port that might prevent charging. When your MagSafe cable is connected properly, you should see a green or orange light on the connector.
If the steps above do not resolve your sleep-related issue, try these additional recommendations.
I hope this information helps ....