Symptom Charts

The symptom charts included in this lesson will help you diagnose specific symptoms by following the guidelines set forth in the Apple General Trouble shooting Flowchart. Because cures are listed on the charts in the order of most likely solution to least likely, try the cures in the order presented. Verify whether or not the product continues to exhibit the symptom. If the symptom persists, try the next cure.

Startup Failures

When testing a computer for the following symptoms, remove the side access panel so you can better observe or listen for fan movement.

Power-on LED Does Not Illuminate When Power Button Is Pressed, Fans Do Not Spin, and There Is No Boot Tone or Video

1.	Verify that the power outlet is good.
2.	Replace the power cord.
3.	Reset the logic board. Refer to “Resetting the Logic Board,” earlier in this lesson.
4.	Verify that the power supply cables are fully connected.
5.	Check for trickle voltage on the power supply connector. Refer to “Power Supply Verification,” earlier in this lesson. If verification fails, replace the power supply.
6.	Reseat the front panel board cable.
7.	Replace the front panel board cable.
8.	Test the front panel board and power button using the front panel board troubleshooting tool. Refer to “Front Panel Board Troubleshooting,” earlier in this lesson. If the computer starts up correctly, go to step 9. Otherwise, go to step 12.
9.	Test whether the front panel board or power button is at fault. Remove the installed front panel board and swap it for the known-good front panel board in the front panel board troubleshooting tool. Then connect the troubleshooting tool to the logic board of a known-good Power Mac G5 and start it up using the tool. If the computer does not start up correctly, go to step 10. Otherwise, go to step 11.
10.	Replace the front panel board.
11.	Replace the power button.
12.	Replace the logic board.

Power-on LED Illuminates When Power Button Is Pressed, but Fans Do Not Spin (or Spin Only Momentarily) and There Is No Boot Tone or Video

1.	Reseat the video card. Make sure the video card is fully inserted in the connector and the connector latch secures the end of card.
2.	Reset the logic board. Refer to “Resetting the Logic Board,” earlier in this lesson.
3.	Verify that the power supply cables are fully connected.
4.	Check for trickle voltage on the power supply connector. Refer to “Power Supply Verification,” earlier in this lesson. If verification fails, replace the power supply.
5.	Replace the logic board.

Power-on LED Illuminates When Power Button Is Pressed and Fans Spin Continuously, but There Is No Boot Tone or Video

1.	Reseat the video card. Make sure the video card is fully inserted in the connector and the connector latch secures the end of card.
2.	Verify that the speaker cable is fully seated.
3.	Reset the logic board. Refer to “Resetting the Logic Board,” earlier in this lesson.
4.	Replace the logic board.

Power-on LED Illuminates When Power Button Is Pressed, Fans Spin, and Boot Tone Chimes, but There Is No Video

1.	Reseat the video card. Make sure the video card is fully inserted in the connector and the connector latch secures the end of card.
2.	Reset PRAM. Hold down Command-Option-P-R during startup until you hear the startup sound twice.
3.	Replace the video card.
4.	Reset the logic board. Refer to “Resetting the Logic Board,” earlier in this lesson.
5.	Replace the logic board.

Power-on LED Does Not Illuminate When Power Button Is Pressed, but Fans Spin, Boot Tone Chimes, and There Is Video

1.	Reseat the front panel board cable.
2.	Replace the front panel board cable.
3.	Test the front panel board and power button using the front panel board troubleshooting tool. Refer to “Front Panel Board Troubleshooting,” earlier in this lesson. If the computer starts up correctly, go to step 4. Otherwise, go to step 7.
4.	Test whether the front panel board or power button is at fault. Remove the installed front panel board and swap it for the known-good front panel board in the front panel board troubleshooting tool. Then connect the troubleshooting tool to the logic board of a known-good Power Mac G5 and start it up using the tool. If the computer does not start up correctly, go to step 5. Otherwise, go to step 6.
5.	Replace the front panel board.
6.	Replace the power button.
7.	Replace the logic board.

Other Failures

Air Deflector Sensor Board

1.	Reseat the air deflector sensor board cable.
2.	Replace the air deflector sensor board.
3.	Replace the logic board.
4.	Replace the enclosure.

Hard Drive (Kernel Panics, Hard Drive Does Not Mount, or Performance Slows When Second Hard Drive Is Installed)

1.	Replace the hard drive guide screws.
2.	Replace the hard drive.

Optical Drive

1.	Replace the optical drive cable.
2.	Replace the optical drive.
3.	Replace the logic board.

FireWire Port (Front Panel A)

1.	Reseat the front panel board cable.
2.	Replace the front panel board cable.
3.	Replace the front panel board.
4.	Replace the logic board.

FireWire Port (Rear A <-> B)

Replace the logic board.

FireWire Port (rear B <-> B)

Replace the logic board.

Internal Speakers (Left or Right Fails, Boot Tone)

Replace the logic board.

Internal Speakers (High-Pitch Tone)

1.	Replace the power supply.
2.	Replace the logic board.

USB 2.0 (Front Port)

1.	Replace the front panel board cable.
2.	Replace the front panel board.
3.	Replace logic board.

USB 2.0 (Rear-Top Port or Rear-Bottom Port)

Replace the logic board.

Modem

1.	Replace the modem.
2.	Replace the modem filter board.
3.	Replace the logic board.

AirPort

1.	Replace the AirPort Extreme Card.
2.	Replace the antenna card.
3.	Replace the logic board.

Bluetooth

1.	Replace the Bluetooth card.
2.	Replace the antenna card.
3.	Replace the logic board.

Audio IO (Front Line In <-> Headphones)

1.	Replace the front panel board cable.
2.	Replace the front panel board.
3.	Reposition the logic board.
4.	Replace the logic board.

Audio IO (Rear Line In <-> Line Out)

Replace the logic board.

Audio IO (Rear Line Out <-> Line Out)

Replace the logic board.

Fans

Individual Fan Failure

1.	Replace the fan. NOTE You cannot replace the drive fan and blower located between the optical and hard drives. You must replace the enclosure for these two parts.
2.	Replace the logic board.

Media Bay Fans Run at High Speed

1.	Verify that the clear plastic air defiector door is in place.
2.	Verify that the white sensor label is not damaged and is in place on the lower-right tab of the air defiector door.
3.	Verify that the air defiector sensor board is operating properly. NOTE To differentiate a bad sensor label from a bad sensor board, remove the air deflector door. Then slide a folded piece of paper through the slot in the enclosure where the right tab of the air deflector would normally be inserted. If the red LED goes out (but stays on with the door in place), the sensor label on the door is missing or damaged.
4.	Check the sensor cable connection on the logic board (second-from-right connector located directly below the hard drives).
5.	Replace the logic board.
6.	Replace the air defiector sensor board.