Information Technology Reference
In-Depth Information
One common cause of program errors is having one or more program files corrupted because of hard drive errors.
Before you reinstall a program, try repairing the MacBook Air hard drive, as described later in this chapter.
Did you recently change any System Preferences?
If the problem started after you changed MacBook
Air's configuration, try reversing the change. Even something as seemingly innocent as activating a screen
saver can cause problems, so don't rule anything out.
Basic software troubleshooting steps
Figuring out the cause of a problem is often the hardest part of troubleshooting, but by itself it doesn't do you
much good. When you know the source, you need to parlay that information into a fix for the problem. I dis-
cussed a few solutions in the previous section, but here are a few other general fixes you need to keep in mind:
Close all programs.
You can often fix flaky behavior by shutting down all your open programs and starting
again. This is a particularly useful fix for problems caused by low memory or low system resources.
Log out.
Logging out clears the memory and gives you a slightly cleaner slate than merely closing all your
programs. Pull down the Apple menu and choose Log Out
User
(where
User
is your MacBook Air username),
or press Shift+ +Q to log out quickly.
Restart MacBook Air.
If there are problems with some system files and devices, logging out won't help be-
cause these objects remain loaded. By restarting MacBook Air, you reload the entire system, which is often
enough to solve many problems. I discuss various ways of restarting MacBook Air later in this chapter.
Monitoring MacBook Air to look for problems
If MacBook Air feels sluggish or an application is behaving erratically, what might the problem be? Perhaps the
processor is busy with other tasks; perhaps MacBook Air is running low on memory; or perhaps there's a prob-
lem with the hard drive. It could be any of these things, but the only way to tell is to look under the hood, so to
speak, and monitor these aspects of MacBook Air.
MacBook Air's monitoring tools are useful troubleshooters, but they're also good for acquainting yourself with
MacBook Air. Monitoring things like the processor and memory usage regularly (not just when you have a
problem) helps you get a feel for what's normal on MacBook Air, which then helps you better diagnose
MacBook Air when you suspect a problem.
Monitoring CPU usage
The CPU (central processing unit or just processor) is the chip inside MacBook Air that acts as the computer's
control and command center. Almost everything you do on MacBook Air and almost everything that happens
within MacBook Air goes through the CPU. It is, in short, a pretty darned important component, and it pays to
keep an eye on how much MacBook Air's CPU is being taxed by the system. If MacBook Air feels less re-
sponsive than usual, or if a program has become very slow, it could be because the CPU is running at or near
full capacity.
To see if that's the case, you can use Activity Monitor, which gives you a list of everything running on
MacBook Air and tells you, among other things, what percentage of the CPU's resources are being used. Follow
these steps to get started:
1. Click Launchpad in the Dock.
The Finder window opens.
2. Choose Other
→
Activity Monitor.
3. Click the CPU tab at the bottom.
