Apple powermac g3 blue.white Manuales De Servicio
Troubleshooting
General/Logic Board LEDs - 9
DS4 and DS5 = USB power for downstream devices
DS5 = USB port 1- lower
DS4 = USB port 2- upper
When illuminated, these LEDs indicate that the computer is
providing power (+5 V) to downstream USB ports. USB devices do
not need to be connected in order for these LEDs to illuminate.
However, if one or both of the LEDs is not illuminated and a USB
device is/was attached (and the system has completed its boot
process), then the logic board has removed downstream power
because of a trouble condition.
Since the downstream power is controlled individually for each
port, it is possible to have these LEDs in a different state: one off
and one on. This way if one port has troubled USB devices, the
other port can still be functional. These LEDs are not immediately
illuminated at the beginning of a restart or cold power-on. During