The Power Mac G4 computer stops responding or hangs.

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 computer stops responding or hangs.

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 system software is Mac OS 8.6 or higher.

2. If the system is not responding or the system is hanging in a specific application, replace the application.

3. Perform a clean install of system software with the system restore CD that came with the computer.

4. Verify software is compatible with this model of Power Macintosh (contact developer).

5. Start up with extensions off to determine if there are system extension or control panel problems.

6. Run Disk First Aid.

7. Test for bad memory. Run MacTest Pro in loop mode overnight to test the memory. If MacTest Pro finds a bad memory module, or other hardware, replace the hardware in question with a known-good module.

8. Clear parameter RAM. Hold down Command-Option-P-R during startup but before "Welcome to Macintosh" appears.

9. Remove all SDRAM DIMMs and try replacing them one at a time to test. Replace any bad DIMMs.

10. Reset the logic board. Refer to resetting the PMU in article 95037: " Power Mac G4 (AGP Graphics): Resetting the PMU on the Logic Board ".

11. Replace logic board.

12. Replace processor module.