why won't my Mac Air wake up when it's supposed to?

Hello, marjoriefromcamano island.

Thank you for visiting Apple Support Communities.

Here is a troubleshooting article that I would recommend going through when experiencing this issue.

OS X: When your Mac doesn't sleep or wake

http://support.apple.com/kb/TS5357

Cheers,

Jason H.

hi, i also have the same problem that really annoying. i found this issue since i bought a macbook pro 15 early 2011 from my uncle few months ago. he said that the problem started since day one. i upset why didn't he report to the apple store in a first place, he said that the problem didn't bother him. so i started searching for a solution on the internet. i can't even remember how many times I've tried every single solution i found, and I'm sure i I've tried them all, but the problem still persist. but, few days ago i tried logging in with a guest user and put my macbook to sleep for a night and what happened just really surprised me, the mac woke up PERFECTLY, the thing that never happened to me since i bought my uncle's mac. and i wonder what the **** was happening on my main user login and i realised that the guest user doesn't need a password when it wakes from sleep, so i tried to back to my main user login, and disabled the password when log in then put it to sleep overnight, and voila my mac woke up perfectly! tried a few times and the screen freezes when waking up problem never happened since.

did you enable password on your system?

if so, try disabling your password and see what happen.

maybe its not a solution to everyone though, but at least you will know if your mac hardware is doing fine.

thanks