Macintosh Portable: High-Pitched Sound at Startup


When I try to start up my Macintosh Portable, I get a high-pitched sound
through the speaker. The first time, I replaced the logic board. After a
while, the sound came back.

If the Portable has any peripherals (excluding anything plugged into the
serial ports), check them. A failing device may be causing portions of
the logic board to fail.

If the Portable has no extra peripherals, check the keyboard for either
cracks or flexing. These may put it in contact with the case.


Published Date: Feb 18, 2012