General Problem Determination Procedures; Resolving Suspected Power Problems - Lenovo ThinkSystem ST550 7X09 Maintenance Manual

General problem determination procedures

Use the information in this section to resolve problems if the event log does not contain specific errors or the
server is inoperative.
If you are not sure about the cause of a problem and the power supplies are working correctly, complete the
following steps to attempt to resolve the problem:
1. Turn off the server.
2. Ensure that the server is cabled correctly.
3. Remove or disconnect the following devices, one at a time, until you find the failure. Turn on and
configure the server each time you remove or disconnect a device.
• Any external devices
• Surge-suppressor device (on the server)
• Printer, mouse, and non-Lenovo devices
• Each adapter
• Storage drives
• Memory modules until you reach the minimum configuration that is supported for the server
Note: The minimum configuration required for the server to start is one processor and one 8 GB DIMM.
4. Turn on the server.
If the problem is solved when you remove an adapter from the server, but the problem recurs when you
install the same adapter again, suspect the adapter. If the problem recurs when you replace the adapter with
a different one, try a different PCIe slot.
If the problem appears to be a networking problem and the server passes all system tests, suspect a network
cabling problem that is external to the server.

Resolving suspected 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.
Complete the following steps to diagnose and resolve a suspected power problem.
Step 1. Check the event log and resolve any errors related to the power.
Note: Start with the event log of the application that is managing the server. For more information
about event logs, see "Event logs" on page 181.
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
"Specifications" on page 3 to determine the minimum configuration for your server.
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, replace the components in the minimum
configuration one at a time until the problem is isolated.
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Chapter 4 Problem determination
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