Specifications

Troubleshooting Symptom Charts/Sound - 5
3 Use Apple System Profiler to verify that the computer is
recognizing the bus.
4 For USB, test ports with an Apple keyboard or mouse.
5 For FireWire, test by connecting another computer in
FireWire Target Disk Mode. Refer to article 58583: How to
Use FireWire Target Disk Mode.
6 Verify that drivers are installed properly for third party, if
needed.
7 If in Mac OS 9, boot with Mac OS All extension set.
8 Try other port if available.
9 Try a different cable.
10 If self powered make sure that the power supply is connected
and device's LED indicates that it is getting power.
11 Replace logic board.
A USB device not
recognized by
computer
Note: If you are trying to use a serial device with a USB/Serial
adapter, check with the manufacturer of the adapter for
compatibility.
1 Completely shut down, then press the power button to start
the computer.
2 Try known-good Apple USB keyboard or mouse to verify the
port is working properly.
3 Verify current driver for the device is installed.
4 If a camera, turn on camera after initiating download with
camera application.
5 Try the other USB port.
6 Try different USB device on same port.
7 Eliminate chain by plugging in only one peripheral.
8 If in Mac OS 9, select “Mac OS All” in the Extensions
Manager control panel and restart.
9 If in Mac OS 9, troubleshoot extensions and perform a clean
installation of system software.
10 Replace logic board.
Sound
Distorted sound from
speakers
1 Verify sound is correct with external speakers/headphones.
If sound is correct, replace top case.
2 In Mac OS X check balance.
3 Compare same sound with two different units to make sure
that sound is actually distorted.
4 Replace logic board.
No sound from
speaker(s)
1 Use the Software Update control panel to verify that the latest
audio update has been installed.