Apple powermac g3 blue.white サービスマニュアル
Troubleshooting
General/Logic Board LEDs - 11
DS7 & DS8 = Power Indication
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.
DS9 = CPU Bus Request
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.