Universal Serial Bus (Usb) Port Problems; Light Path Diagnostics; Viewing The Light Path Diagnostics Leds - IBM 8853L6U Service Manual

Universal Serial Bus (USB) port problems

The USB ports are shared BladeCenter unit resources. First, make sure that the
USB ports are assigned to the blade server; then, see the following table and
"Solving shared BladeCenter resource problems" on page 108.
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, Types 1885 and 8853," on page 15 to determine which components are CRUs
and which components are FRUs.
v If an action step is preceded by "(Trained service technician only)," that step must be performed only by a
trained service technician.
Symptom
A USB device does not work.

Light path diagnostics

Light path diagnostics is a system of LEDs on the control panel and on various
internal components of the blade server. When an error occurs, LEDs can be lit
throughout the blade server to help identify the source of the error.
After you remove the blade server, you can press and hold the light path
diagnostics switch for a maximum of 25 seconds to light the LEDs and locate the
failing component. The following components have this feature:
v Hard disk drives
v Light path diagnostics panel
v Microprocessors
v Memory modules (DIMMs)

Viewing the light path diagnostics LEDs

Before working inside the blade server to view light path diagnostics LEDs, read the
safety information that begins on page vii and "Installation guidelines" on page 19.
If an error occurs, view the light path diagnostics LEDs in the following order:
1. Look at the control panel on the front of the blade server (see "Blade server
2. To view the light path diagnostics panel and LEDs, complete the following steps:
Action
1. Check the function of the shared BladeCenter unit resources (see "Solving
shared BladeCenter resource problems" on page 108).
2. Make sure that:
v The operating system supports USB devices.
v The correct USB device driver is installed.
3. (Trained service technician only) Replace the system board assembly.
controls and LEDs" on page 4).
v If the information LED is lit, it indicates that information about a suboptimal
condition in the blade server is available in the BMC log or in the
management-module event log.
v If the blade-error LED is lit, it indicates that an error has occurred; go to step
2.
a. Remove the blade server from the BladeCenter unit.
b. Place the blade server on a flat, static-protective surface.
93
Chapter 5. Diagnostics