Specifications

14 - Power Mac G4 (Mirror/FW800) Troubleshooting
Symptom Charts
Startup
System is completely dead (no fan movement and power LED is not lit)
1.
Verify the power outlet is good.
2. Replace the power cord.
3. Make sure the voltage switch on the back of the power supply is set to the correct
voltage.
4. Reset the logic board. Refer to “Resetting the PMU on the Logic Board” in this
chapter.
5. Check for trickle voltage on the power supply connector. Refer to “Power Supply
Verification” in this chapter. If verification fails, replace the power supply.
6. Disconnect external devices, including the monitor, and start up the computer.
7. Remove internal cards and start up the computer.
8. Disconnect internal hard drives from the logic board and start up the computer.
9. Check the modem connector. If the connector has any bent pins, replace the logic
board.
10. Check the pins in the power supply connector on the logic board. If the pins are bent,
replace the logic board.
11. Replace the logic board.
Memory error message appears on the screen
1. Reseat the DIMMs.
2. Verify that only the correct SDRAM DIMMs are installed.
3. Replace the DIMMs one at a time and test until all bad DIMMs are replaced with
known-good modules.
Flashing question mark appears on the screen
1. Start up from the system restore CD and check to see if the hard drive shows up in the
Disk Utility. If it does, go to step 2. If it does not, go to step 4.
2. Run Disk Utility. Update the driver and restart the computer.
3. Reinstall system software using the system restore CD that came with the computer.
4. If you are starting up in Mac OS 9, turn off your Mac OS 9 system extensions:
• Start up the computer while holding down the Shift key.
• If the computer is set to start up from another computer on your network, check
that the Ethernet cables are firmly connected, then restart the computer. If the
computer has trouble connecting to the network, check that the startup computer or
server is not down.