Lenovo BladeCenter HS23 1929, Problem Determination And Service Manual

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Light path diagnostics
Use this information as an overview of light path diagnostics.
Light path diagnostics is a system of LEDs on the control panel and on various internal components of the
blade server or expansion unit. When an error occurs, LEDs can be lit throughout the blade server or
expansion unit to help identify the source of the error.
After you remove the blade server or expansion unit, you can press and hold the power button for a
maximum of 25 seconds to light the LEDs and locate the failing component.
Viewing the light path diagnostics LEDs in the blade server
Use this information to locate and identify the light path diagnostics LEDs.
Before you work inside the blade server to view light path diagnostics LEDs, read “Safety” on page iii and
“Installation guidelines” on page 37.
If an error occurs, view the light path diagnostics LEDs in the following order:
Step 1. Look at the control panel on the front of the blade server (see “Blade server controls and LEDs” on
page 4).
• If the information LED is lit, it indicates that information about a suboptimal condition in the
blade server is available in the IMM2 log or in the Advanced-Management-Module event log.
• If the blade-error LED is lit, it indicates that an error has occurred; view the light path diagnostics
panel (located under the blade server) and LEDs on the system board to isolate the failing
component.
Step 2. To view the light path diagnostics panel and LEDs, complete the following steps:
a. Remove the blade server from the BladeCenter unit. See “Removing the blade server from the
BladeCenter unit” on page 39.
b. Place the blade server, bottom side up, on a flat, static-protective surface.
c. Press and hold the power button to light the LEDs on the light path diagnostics panel.
d. If the INTERNAL LP LED is lit, it indicates that an error has occurred on a component on the
system board. Complete the following steps:
1. Remove the cover from the blade server. See “Removing the blade server cover” on page
72.
2. Press and hold the power button to light the LEDs of the failing components in the blade
server. The LEDs will remain lit for as long as you press the switch, to a maximum of 25
seconds.
The following illustration shows the locations of the system-board error LEDs.
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BladeCenter HS23 Blade ServerProblem Determination and Service Guide