Apple powermac g3 blue.white Service Manual

 

 Troubleshooting

General/Logic Board LEDs - 11

 

In a working unit, these LEDs should be in sync with each other: 

both on or both off. If one LED is on and the other is off, there is a 

problem. 

 

When illuminated, this LED indicates that the CPU is requesting 

the bus. This LED will rarely glow as brightly as the others (like 

the Ultra ATA LED) given that the CPU is not always requesting the 

bus, and when it does, the period of time is short. As a result, you 

may need to watch this LED much more carefully than the others to 

tell if there is activity. If this LED is ever on continuously and 

bright, then the system is troubled and likely hung.