When your MacBook is shut it should be in Sleep mode. It should draw almost no power and do next to nothing. But if it remains active with discs spinning and programs running you may have a problem. Here's how to make your MacBook sleep when the lid is closed. See all Apple how to articles.
Closing the lid on your laptop should put it to sleep. The discs won't spin, nothing untoward will take place and you can rest in the knowledge that - while not switched off - your laptop is all but inactive. Indeed, MacBooks are designed to be put to sleep by closing the lid, as this process draws very little power and makes them much quicker to come to life when you need them to.
Unfortunately since the OS X 10.7 Lion update last year there have been some reports of Apple laptops that refuse to sleep nicely. If you can hear the fans whirring away when your MacBook is closed, consider it a clue that all is not well. Conclusive proof will take the form of opening your 'sleeping' MacBook and finding active applications running - perhaps AV if you have it, or some form of networking software.
It's not catastrophic if this is the case, just be aware that if your PC isn't sleeping as much as it should its parts may wear our more quickly than they otherwise would.
Here then, is how to ensure that your MacBook stays asleep when the lid is closed.
Make MacBook sleep when lid is closed
The simplest way to put any Mac to sleep is to hold down Alt + Command + Eject for two seconds or so. When the screen switches off, you know the laptop is asleep. Close the screen, and all should be well.
However, if this doesn't work and your Mac is refusing to sleep, there is a tweak that some reports have suggested will work to solve the problem. It's neither official nor guaranteed, but it won't hurt your Mac and will be worth a try. It does, however, require you to switch off sharing and then re-enable it - the idea being that it is your Mac trying to talk to other computers that is causing the problem, and that you need to tell it once again in exactly what ways it should communicate. (In essence, you are switching off and on again all the sharing options.)
To try this solution, open System Preferences, then Sharing. Take a screenshot. Then untick all the options that are currently ticked, and exit System Preferences. Now restart your Mac.
Now you can go back into System Preferences and re-enable all the Sharing options you just disabled, using the screenshot as a reference. When next you put your MacBook to sleep, it should stay there.
We'd be delighted to know if this works, so let us know in the comments below.
This MacBook should be asleep... but is it?