The Power Mac G4 shuts down almost immediately.

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 Mac G4 shuts down almost immediately.

Products affected

• Power Mac G4
• Macintosh Server G4

DANGER! This procedure exposes you to high voltages that can result in death or serious injury. DO NOT ATTEMPT THIS PROCEDURE IF YOU HAVE NOT BEEN CERTIFIED AS AN APPLE-AUTHORIZED TECHNICIAN.

1. Verify the power outlet is good. Try a known-good power cord.

2. Ensure the voltage switch on the back of the power supply is set to the correct voltage.

3. Power Macintosh G4 (PCI Graphics): Reset Cuda chip and try again. See article 95065 " Power Mac G4 (PCI Graphics): Resetting the Cuda Chip " .

4. Reset the logic board:
- Power Macintosh G4 (AGP Graphics): Refer to article 95037: " Power Mac G4 (AGP Graphics/Gigabit Ethernet): Resetting the PMU on the Logic Board ".
-Power Macintosh (PCI Graphics): Refer to article 95066: " Power Mac G4 (PCI Graphics): Resetting the Logic Board".

5. Replace power supply.