Service manual

Troubleshooting 3-73
Figure 3–1 shows the location and condition (on or off) of LEDs on the OCP, AC input
box, 48V power supply, PCI power supply, local I/O riser, PSM, and the main and
auxiliary power modules when the system is running.
The only LEDs visible when the cabinet doors are closed are those on the OCP. When
the Halt LED on the OCP is lit, AC is applied to the system, Vaux is on, and the system
cannot be powered on remotely. When the Power LED on the OCP is lit, the system is
running. And when the Secure LED is on, the system is running but cannot be
controlled remotely.
The following comments assume the system is powered on, cabinet doors are open, and
faceplates removed so all LEDs are visible. Note that the position of LEDs may be the
reverse order of that shown in Figure 3–1 because of different QBB backplane
orientations. Also note that LEDs could be off because the system/QBB was powered off
remotely or that the QBB was powered off because of a diagnostic failure during power-up.
AC input box LEDs – If the LED(s) are off, either the AC input box is broken or AC is
not reaching the box from the wall.
48V power supply and PCI power supply LEDs – If Vaux LEDs are off, either the
power supplies are broken or AC is not getting from the AC input box(s) to them. If the
48V LED on a 48V power supply or the Power OK LED on a PCI power supply is off,
there is a power problem. See Section 3.1.
Local I/O riser LED – If the Power On LED is off, a power problem is likely. See
Section 3.1.
PSM LEDs – If the QBB DC Good LED is off, check the LEDs on the main and auxiliary
power modules. If they are fine, then a problem with the PSM or the QBB backplane or
some other power problem is likely. See Section 3.1.
If the PSM DC OK LED is off, the converters on the PSM are broken unless there are
other failure indications. The QBB will not power up, the PSM will remain in the
reset/initialize state, and the Reset/Initialize LED will be lit.
If the Reset/Initialize LED is lit, the PSM is either executing self-test, failed self-test, or
there is some other PSM/power problem. The QBB will not power up.
If the Hot Swap DC OK LED is off, the PSM DC OK LED should also be off and the
system will not power up.
If the Vaux OK LED is off, Vaux is not getting to the module or it is broken. The same is
true for the Vaux LEDs on the main and auxiliary power modules.
Main or auxiliary power module LEDs – If the Module OK LED is off, the module is
broken unless there are other power problems. If any of the overtemp LEDs are on, the
QBB will power down.
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