IBM 7940, Problem Determination And Service Manual

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Link LEDs (Ethernet): These LEDs are on the dual Ethernet connector. When
either LED is lit, it indicates that there is an active link between the server and the
network device that is connected to the left or right connector.
Video connector: Connect a monitor to this connector.
NMI switch: This switch is reserved for use by service technicians only.
Power-cord connector: Connect the power cord to this connector.
AC power LED: The power supply has an ac power LED and a dc power LED.
When the ac power LED is lit, it indicates that sufficient power is coming into the
power supply through the power cord. During typical operation, both the ac and dc
power LEDs are lit. For additional information about the ac power and dc power
LEDs, see “Power-supply LEDs” on page 99.
DC power LED: The power supply has a dc power LED and an ac power LED.
When the dc power LED is lit, it indicates that the power supply is supplying
adequate dc power to the system. During typical operation, both the ac and dc
power LEDs are lit. For additional information about the ac power and dc power
LEDs, see “Power-supply LEDs” on page 99.
Serial connector: Connect a 9-pin serial device to this connector.
System locator LED: This LED can be lit remotely by the system administrator to
aid in visually locating the server. If the server supports IBM Director, you can use
IBM Director to light this LED remotely. A system locator LED is also on the front of
the server.
USB connectors: Connect a USB device to any of these four connectors.
Gigabit Ethernet 1 (LAN 1) connector: Use this connector to connect the server
to a network.
Gigabit Ethernet 2 (LAN 2) connector: Use this connector to connect the server
to a network.
LAN activity LEDs (Ethernet): These green LEDs are on the dual Ethernet
connector. When either LED flashes, it indicates that data is being transmitted or
received between the server and the local area network (LAN) device that is
connected to the left or right connector. The flashing frequency is proportional to the
amount of traffic on the network link.
Internal LEDs, connectors, and jumpers
The illustrations in this section show the connectors, LEDs, and jumpers on the
internal boards. The illustrations might differ slightly from your hardware.
System-board internal and option connectors
The following illustration shows the connectors for internal and user-installable
optional devices.
Chapter 1. Introduction
7