Rich,
What 'sound' went out on your Cube? I'm asking because the Cube doesn't have a sound card, period. The modem can make a sound. The original speakers are connected via USB, are therefore Digital - no sound card.
The speakers can fail, the USB ports can fail. The speakers can be replaced. The USB Ports are part of the Mobo, if they are bad, change Mobo's - switch that from your spare.
The Power Mac G4 Cube has the following sound features:
Separate stereo speakers and digital amplifier module
Headphone jack (on the digital amplifier module)
Sound input and output through the USB and FireWire ports.
Amplifier and Speakers
The Power Mac G4 Cube comes with a pair of stereo speakers and a separate digital audio amplifier. The connection from the computer to the amplifier is a single cable that carries USB signals and power. Power is provided by the USB ports on the G4 Cube or on an Apple display that uses the Apple display connector (ADC).
The digital amplifier module supplies up to 10 W per channel.
The speakers have a frequency response of 80 Hz to 20 kHz.
Headphone Jack
A headphone jack is located on the digital audio amplifier module. The headphone jack is a stereo mini-jack for connecting a pair of low-impedance headphones. It can also be used to drive a 10K-ohm audio line input.
The recommended minimum impedance is 32 ohms. Headphones with lower impedance can be used, but with some degradation in performance.
Digital Audio
The Power Mac G4 Cube supports third-party digital audio peripherals connected to the USB ports. For information about USB audio class devices, see the references in Apple's Developer docs for USB Interface.
Regards,
Dave
