Apple PowerBook (Duo, 2300 Series) - Manual (Page 90)

The computer makes an unusual sound at startup.
m If you hear an unfamiliar startup sound, start up the computer with the
Disk Tools disk that came with your computer (if you have an external
floppy disk drive or a Duo Dock Plus). If the computer does not start up, or
if the hard disk icon does not appear, the hard disk may need repair.
Contact an Apple-authorized service provider or call the Apple Assistance
Center. If the hard disk icon does appear, see Chapter 7, “Diagnostic
Techniques.”
m There may be a problem with the parameter RAM. Reset the PRAM, as
explained in the previous section.
m There may be a problem with a RAM expansion card. If you installed a
RAM expansion card in your computer, check the instructions in the
Technical Information booklet that came with your computer to make sure
the card is properly installed. If you purchased an expansion card from a
third-party manufacturer, contact the manufacturer for help.
See also “The Computer Makes Unusual Sounds” in the section “Other
Problems While Working” later in this chapter.
The computer starts up, but the desktop doesn’t appear.
m The screen brightness may be turned down. Adjust the brightness control
(¤), located to the right of the display.
m The computer may be trying to start up using an external hard disk that
does not contain the correct version of system software. Disconnect the
external hard disk and restart your computer.
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 “Checking Your System Software Extensions” in Chapter 7 and
try the steps given.
m If you see the following icon on the screen, your PowerBook is in SCSI
disk mode. See “Quitting SCSI Disk Mode” in the section “Connecting
SCSI Devices” in Chapter 3 for more information.
82 Chapter 6