Possible solution to the black screen problem

My macbook air is 13-inch, 128GB

OS is os x 10.8.4

My problem is:

After closing the lid, the mac goes to sleep. And after a time which is longer than the value of standbydelay setting (to know what is standbydelay plz refer to https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages /man1/pmset.1.html), open the lid, then the screen goes black directly, no login screen, but the backside logo is lighting, the keyboard is lighting, and the screen has faint light, not complete dark.

My solution:

The following is useless or just temporal

1. Reset SMC or PRAM

2. Select startup disk

3. Reinstall OS X

4. Delete sleepimage file

The following method is not good, so i don't give it a try

pmset -a hibernatemode 0 (disable Safe Sleep, which can result in data loss)

The following is what I use and useful until now

Click System Preferences

Click Power Saver

Click Lock to lock it

Import plz Note: If u reboot it, u need to Lock it again. Because the system unlock it after a reboot or shutdown-start.

Apparently, it's another OS bug which is so ugly. Does apple have a test team?

Try it and check it for a few days

If it works, plz post it to let others and me know