IBM xSeries 235, Maintenance & Troubleshooting

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Fans 1 and 2 LEDs: These LEDs provide status information about fans 1 and 2
(the rear fans in connector J25). For additional information, see “Light Path
Diagnostics” on page 34.
Ethernet link status LED: This LED is on the Ethernet connector. When this LED
is on, there is an active connection on the Ethernet port.
PCI-X slot attention LED: This green LED flashes approximately once per second
when it is on. This LED is visible from the rear of the server and from inside the
server. The meaning of the attention LED is defined by your operating system. For
an illustration showing this LED on the system board, see “LEDs for Active PCI
slots” on page 32.
NMI button: The Non-Maskable Interrupt (NMI) button is for service use only.
DC power LED: This green LED provides status information about the power
supply. During typical operation, both the ac and dc power LEDs are on. For any
other combination of LEDs, see “Power-supply LED errors” on page 141.
AC power LED: This green LED provides status information about the power
supply. During typical operation, both the ac and dc power LEDs are on. For any
other combination of LEDs, see “Power-supply LED errors” on page 141.
Operator information panel
The following illustration shows the status LEDs on the operator information panel
on the front of the server.
TX
RX
OK
1
Power-on
LED
POST-
complete LED Hard disk drive
activity LED
Information
LED
System-
error LED Ethernet transmit/
receive activity LED
/
Important: If the power-on LED is off, it does not mean there is no electrical
current present in the server. The LED might be burned out. To remove
all electrical current from the server, you must unplug the server power
cords from the electrical outlets or from the uninterruptible power
device.
Power-on LED: When this green LED is on, power is present in the server.
When this LED flashes, the server is in Standby mode (the system operating
system is turned off and ac current is present). When this LED is off, the power
subsystem, the ac power, or an LED has failed.
POST-complete LED: This green LED is on when POST is completed without
any errors.
Hard disk drive activity LED: This green LED flickers when there is activity on
a hard disk drive.
Information LED: When this amber LED is on, the server power supplies are
nonredundant, or some other noncritical event has occurred. The event is
Chapter 1. General information
7