Chapter 5
Troubleshooting
System Board Diagnostic LEDs
100
System Board Diagnostic LEDs
There are three additional LEDs that can help when troubleshooting the system. These LEDs are located on
the system board close to the back of the system and can be viewed through the small cooling holes in the
system case.
Figure 5-3
Location of the STBY, F/W and BMC LEDs
Table 5-25
System Board LEDs
LED
Description
STBY
(power good)
This green standby LED comes on as soon as the system’s power cord is plugged in. If
this light is off when the system is plugged in, check the AC power cord, reseat the
power supply, and if this does not work, replace the power supply.
BMC
(heartbeat)
A few seconds after the system is plugged in this green LED starts blinking, which
means that the baseboard management controller (BMC) is alive. If this LED is not
blinking and the STBY (standby) LED is on, you may have to replace the base unit.
F/W
A few seconds after the system power is turned on, the system firmware code fetch
green LED comes on indicating that the firmware has started the boot process. If this
LED does not come on, you may have to replace the base unit.
System Board (enlarged)
STBY
F/W
BMC
System Board
