IBM 8841 - eServer xSeries 236, Installation Manual, Page: 65 / 100

Universal Serial Bus device problems
Symptom Suggested action
A USB device does not work. Make sure that:
v
You are not trying to use a USB device during POST if a standard (non-USB)
keyboard is connected to the keyboard connector. If a standard (non-USB)
keyboard is connected to the keyboard connector, the USB is disabled, and no
USB device will work during POST.
v The correct USB device driver is installed.
v
The operating system supports USB devices.
If the problem remains, call for service.
Light path diagnostics
The following illustration shows the remind button and the LEDs on the light path
diagnostics panel. The light path diagnostics panel is inside the server under the
left-side cover and the error LEDs are also visible through the left-side cover.
CPU VRM S_ERR
MEMORY
DASD/
RAID
NMI SERVICE
PROCESSOR
BUS
FAN
POWER
SUPPLY
PCI
BUS
2
1
CONFIG
TEMP
REMIND
Use the remind button on the light path diagnostic panel to acknowledge that an
error has occurred without taking further action. When you push the remind button
the system error LED will flash every 2 seconds until the error is fixed. If another
error occurs the system error LED will then stop flashing and return to a solid on
state.
For more information about light path diagnostics, see the Hardware Maintenance
Manual and Troubleshooting Guide on the IBM xSeries Documentation CD.
Diagnosing problems using the light path diagnostics
LEDs in three locations on the server are available to help you diagnose problems
that might occur during installation. Use them in the following order:
1. Operator information panel - Look at this panel first. If a system error has
occurred, the system-error LED on the front of the server is lit.
Chapter 6. Solving problems
51