IBM x3550 - System - 7978, Problem Determination And Service Manual

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Universal Serial Bus (USB) port problems
v Follow the suggested actions in the order in which they are listed in the Action column until the problem
is solved.
v
See Chapter 3, “Parts listing, Type 7978 and 1913 server,” on page 29 to determine which components are
customer replaceable units (CRU) and which components are field replaceable units (FRU).
v If an action step is preceded by “(Trained service technician only),” that step must be performed only by a
trained service technician.
Symptom Action
A USB device does not work.
1. Make sure that:
v The correct USB device driver is installed.
v
The operating system supports USB devices.
2. Make sure that the USB configuration options are set correctly in the
Configuration/Setup Utility program (see the User’s Guide on the IBM System x
Documentation CD for more information).
3. If you are using an external USB hub, disconnect the USB device from the hub
and connect it directly to the server.
Video problems
See “Monitor problems” on page 129.
Light path diagnostics
Light path diagnostics is a system of LEDs on various external and internal
components of the server. When an error occurs, LEDs are lit throughout the
server. By viewing the LEDs in a particular order, you can often identify the source
of the error.
When LEDs are lit to indicate an error, they remain lit when the server is turned off,
provided that the server is still connected to power and the power supply is
operating correctly.
Before working inside the server to view light path diagnostics LEDs, read the
safety information that begins on page “Safety” on page vii and “Handling
static-sensitive devices” on page 40.
If an error occurs, view the light path diagnostics LEDs in the following order:
1. Look at the operator information panel on the front of the server.
v
If the information LED is lit, it indicates that information about a suboptimal
condition in the server is available in the BMC log or in the system-error log.
v
If the system-error LED is lit, it indicates that an error has occurred; go to
step 2 on page 137.
The following illustration shows the operator information panel.
136
IBM System x3550 Type 7978 and 1913: Problem Determination and Service Guide