5137ch04.fm
Draft Document for Review October 14, 2014 10:19 am
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IBM Power Systems E870 and E880 Technical Overview and Introduction
Light Path
The Light Path LED function is for scale-out systems that can be repaired by clients. In the
Light Path LED implementation, when a fault condition is detected on the POWER8
processor-based system, an amber FRU fault LED is illuminated (turned on solid), which is
then rolled up to the system fault LED. The Light Path system pinpoints the exact part by
lighting the amber FRU fault LED that is associated with the part that must be replaced.
The service person can clearly identify components for replacement by using specific
component level identify LEDs, and can also guide the IBM SSR directly to the component by
signaling (flashing) the FRU component identify LED, and rolling up to the blue enclosure
Locate LED.
After the repair, the LEDs shut off automatically when the problem is fixed. The Light Path
LEDs are only visible while system is in standby power. There is no gold cap or battery
implemented.
Service labels
Service providers use these labels to assist with maintenance actions. Service labels are in
various formats and positions, and are intended to transmit readily available information to the
IBM SSR during the repair process.
Several of these service labels and their purposes are described in the following list:
Location diagrams
are strategically positioned on the system hardware and relate
information about the placement of hardware components. Location diagrams can include
location codes, drawings of physical locations, concurrent maintenance status, or other
data that is pertinent to a repair. Location diagrams are especially useful when multiple
components are installed, such as DIMMs, sockets, processor cards, fans, adapter, LEDs,
and power supplies.
Remove or replace procedure labels
contain procedures that are often found on a cover of
the system or in other locations that are accessible to the IBM SSR. These labels provide
systematic procedures, including diagrams, detailing how to remove and replace certain
serviceable hardware components.
Numbered arrows
are used to indicate the order of operation and serviceability direction of
components. Various serviceable parts, such as latches, levers, and touch points, must be
pulled or pushed in a certain direction and order so that the mechanical mechanisms can
engage or disengage. Arrows generally improve the ease of serviceability.
The operator panel
The operator panel on a POWER processor-based system is an LCD display (two rows by
16 elements) that is used to present boot progress codes, indicating advancement through
the system power-on and initialization processes. The operator panel is also used to display
error and location codes when an error occurs that prevents the system from booting. It
includes several buttons, enabling an IBM SSR or client to change various boot-time options
and for other limited service functions.
Concurrent maintenance
The IBM POWER8 processor-based systems are designed with the understanding that
certain components have higher intrinsic failure rates than others. These components can
include fans, power supplies, and physical storage devices. Other devices, such as I/O
adapters, can begin to wear from repeated plugging and unplugging. For these reasons,
these devices are designed to be concurrently maintainable when properly configured.
Concurrent maintenance is facilitated because of the redundant design for the power
supplies, fans, and physical storage.
