Power Mac G4 (PCI Graphics): Resetting the Cuda Chip

The Cuda is a microcontroller chip on the Power Macintosh G4 (PCI Graphics) logic board. Whenever you have a Power Macintosh G4 (PCI Graphics) computer that fails to power up, you should follow this procedure before replacing any modules. This article explains how to reset the Cuda chip on the Power Mac G4 (PCI Graphics).

This article covers repair procedures for authorized service providers on selected Apple products, but we have published them in the Knowledge Base for the general public for educational purposes. At this time, there are a limited number of repairs that a customer can perform and these are covered under the customer installable parts program http://www.info.apple.com/installparts. If you have not been authorized to perform these procedures, please contact Apple (800-APL-CARE in the USA) or your local authorized service provider to schedule a repair.

Symptom

The Power Macintosh G4 (PCI Graphics) computer that fails to power up. Many system problems can be resolved by resetting the Cuda chip. The function of the Cuda chip is to:

• Turn system power on and off.
• Manage system resets from various commands.
• Maintain parameter RAM (PRAM).
• Manage the real-time clock.

Products affected

• Power Mac G4 (PCI Graphics)

Solution

Press the Cuda reset button on the logic board to reset the Cuda chip. The Cuda reset button is located to the right of the battery. Note: If the computer still fails to power up, refer to article 95066: "Power Mac G4 (PCI Graphics): Resetting the Logic Board".