Apple MacBook Air (11-inch, Mid 2011) - Manual (Page 47)

47 Chapter 3 Problem, Meet Solution
5 When the Apple Hardware Test main screen appears (after about 45 seconds), follow
the onscreen instructions.
6 If Apple Hardware Test detects a problem, it displays an error code. Make a note of the
error code before pursuing support options. If Apple Hardware Test doesn’t detect a
hardware failure, the problem may be software related.
Important: If the Apple Hardware Test doesn’t appear after restarting, hold down
Option-D and restart the computer to access the Apple Hardware Test software from
the Internet. Your computer must be connected to a network that has access to the
Internet.
Problems with Your Internet Connection
Your MacBook Air has a Network Setup Assistant application to help you set up an
Internet connection. Open System Preferences and click Network.
Click the “Assist me” button to open Network Setup Assistant.
If you have trouble with your Internet connection, try using Network Diagnostics.
To use Network Diagnostics:
1 Choose Apple () > System Preferences.
2 Click Network and then click “Assist me.”
3 Click Diagnostics to open Network Diagnostics.
4 Follow the onscreen instructions.
If Network Diagnostics can’t resolve the problem, there may be a problem with the
Internet service provider (ISP) you are trying to connect to, with an external device you
are using to connect to your ISP, or with the server you are trying to access.