Solving Power Problems; Solving Ethernet Controller Problems - Lenovo System x3750 M4 Installation And Service Manual

See "Monitor and video problems" on page 188.

Solving power problems

Use this information to solve power problems.
Power problems can be difficult to solve. For example, a short circuit can exist anywhere on any of the
power distribution buses. Usually, a short circuit will cause the power subsystem to shut down because of
an overcurrent condition. To diagnose a power problem, use the following general procedure:
Step 1. Check the IMM2 event log and resolve any errors related to the power (see "Power problems" on
page 192).
Step 2. Check for short circuits, for example, if a loose screw is causing a short circuit on a circuit board.
Step 3. Remove the adapters and disconnect the cables and power cords to all internal and external
devices until the server is at the minimum configuration that is required for the server to start (see
"Solving undetermined problems" on page 198 for the minimum configuration).
Step 4. Reconnect all ac power cords and turn on the server. If the server starts successfully, reseat the
adapters and devices one at a time until the problem is isolated.
If the server does not start from the minimum configuration, see "Power-supply LEDs" on page 170 to
replace the components in the minimum configuration one at a time until the problem is isolated.

Solving Ethernet controller problems

Use this information to solve Ethernet controller problems.
The method that you use to test the Ethernet controller depends on which operating system you are using.
See the operating-system documentation for information about Ethernet controllers, and see the Ethernet
controller device-driver readme file.
Try the following procedures:
• Make sure that the correct device drivers, which come with the server are installed and that they are at
the latest level.
• Make sure that the Ethernet cable is installed correctly.
– The cable must be securely attached at all connections. If the cable is attached but the problem
remains, try a different cable.
– If you set the Ethernet controller to operate at 100 Mbps or 1000 Mbps, you must use Category
5 cabling.
• Determine whether the hub supports auto-negotiation. If it does not, try configuring the integrated
Ethernet controller manually to match the speed and duplex mode of the hub.
• Check the Ethernet controller LEDs on the rear panel of the server. These LEDs indicate whether there
is a problem with the connector, cable, or hub.
– The Ethernet link status LED is lit when the Ethernet controller receives a link pulse from the hub. If the
LED is off, there might be a defective connector or cable or a problem with the hub.
– The Ethernet transmit/receive activity LED is lit when the Ethernet controller sends or receives data
over the Ethernet network. If the Ethernet transmit/receive activity LED is off, make sure that the hub
and network are operating and that the correct device drivers are installed.
• Check the LAN activity LED on the rear of the server. The LAN activity LED is lit when data is active on
the Ethernet network. If the LAN activity LED is off, make sure that the hub and network are operating
and that the correct device drivers are installed.
• Check for operating-system-specific causes of the problem, and also make sure that the operating
system drivers are installed correctly.
• Make sure that the device drivers on the client and server are using the same protocol.
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Chapter 4 Troubleshooting
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