Specifications
Power Mac G5 (Late 2005) Troubleshooting — Symptom Charts 144
Symptom Charts
How to Use the Symptom Charts
The Symptom Charts included in this chapter will help you diagnose specic symptoms related
to the product. Because cures are listed on the charts in the order of most likely solution, 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.
Note: If a cure instructs you to replace a module, reinstall the original module before you
proceed to the next cure.
Important: The only way to shut o power completely to the computer and display is to
disconnect their power plugs from the power source. Make sure the power cords to the
computer and display are within easy reach.
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.
Note: Be sure to check the “DDR Memory” and “Power-On Self Test” topics in the General
Information section of this chapter. Incorrect installation of DIMMs or incompatible memory will
not allow the system to start up correctly. For information on how to correctly install DIMMs, see
the “Memory (DIMMs)” topic in the Take Apart chapter.
Power-on LED does not illuminate when power button is pressed, fans do not
spin, and there is no boot tone or video
Verify power outlet is good.
Check that diagnostic LED 4 is on when the power cord is connected and the air deector is
removed.
Replace power cord.
Check that diagnostic LED 3 is on when the power cord is connected and the air deector is
removed.
Reset the logic board. Refer to “Resetting the Logic Board” in this chapter.
Verify power supply cables are fully connected and power bus bar screws are tightened.
Verify that processors are properly seated. Check diagnostic LED 1 and/or LED 6.
1.
2.
3.
4.
5.
6.
7.