Power Mac G4: Screen Lights Up but Nothing is Displayed on the Screen
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 boot tone is present and screen lights up, but nothing is displayed on screen.
Products affected
- Power Mac G4
- Macintosh Server G4
- Macintosh Server G4 with Mac OS X Server
1. Check video cable/card connections.
2. Reset the Cuda chip. Refer to article 95065: "Power Macintosh G4 (PCI Graphics): Resetting the Cuda Chip".
3. Reset the logic board. Power Mac G4 (AGP Graphics): Refer to resetting the PMU in article 95037: "Power Mac G4 (AGP Graphics/Gigabit Ethernet): Resetting the PMU on the Logic Board ". If you have a Power Macintosh G4 (PCI Graphics): Refer to article 95066: "Power Macintosh G4 (PCI Graphics): Resetting the Logic Board".
4. Reseat all PCI cards and SDRAM.
5. Reseat processor module.
6. Test with known-good monitor. Replace monitor if necessary. Refer to appropriate monitor manual to troubleshoot defective monitor.
7. Replace processor module.
8. Replace logic board.