Apple PowerBook (3400 series) - Manual (Page 97)

The computer displays a flashing question mark icon.
m This icon usually means that the computer can’t find system software on
any disks attached to the computer. If the computer is connected to any
external hard disks, make sure they are turned on. Then restart the
computer. If the problem recurs, the hard disk or its system software may
be damaged. See Chapter 8.
m Turn off the computer, disconnect all external devices except the power
adapter, and restart the computer. If the computer starts up, turn to
“Problems with Equipment Connected to Your Computer ” later in
this chapter.
The computer freezes or displays an error message during startup.
m Turn off the computer, disconnect all external devices except the power
adapter, and restart the computer. If the computer starts up, turn to
“Problems with Equipment Connected to Your Computer” later in
this chapter.
m Start the computer, holding down the Shift key until you see the message
“Extensions off” in the Welcome to Macintosh box. If the computer starts
up, turn to Chapter 8.
About the codes in error messages: The number codes in error messages are
used in software development. Sometimes they can help a technician narrow
down the source of a problem. However, the codes are usually too general or
technical in nature to help you diagnose a problem yourself.
When the computer starts up, a message says there is not enough memory.
There may not be enough memory to load all the system software extensions
you’ve installed. Restart the computer, holding down the Shift key until you
see the message “Extensions off” in the Welcome to Macintosh box. Then try
the following to increase available memory:
m Turn on virtual memory (VM) in the Memory control panel, or increase
the VM size if it’s already on. Your PowerBook can deliver good
performance with VM set to two to three times the amount of actual RAM
in the computer.
97 Tips and Troubleshooting