IBM Power 780 Technical Overview And Introduction page 199

In these situations, Guiding Light waits for the servicer's indication of what failure to attend
first and then illuminates the LEDs to the failing component.
Data centers can be complex places, and Guiding Light is designed to do more than identify
visible components. When a component might be hidden from view, Guiding Light can flash a
sequence of LEDs that extends to the frame exterior, clearly
representative to the correct rack, system, enclosure, drawer, and component.
Service labels
Service providers use these labels to assist in doing maintenance actions. Service labels are
found in various formats and positions, and are intended to transmit readily available
information to the servicer during the repair process.
Several of these service labels and their purposes are described in the following list:
Location diagrams are strategically located on the system hardware, relating information
regarding 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 cards, LEDs, and
power supplies.
Remove or replace procedure labels contain procedures often found on a cover of the
system or in other spots that are accessible to the servicer. 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 a four-row by 16-element LCD
display 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 a service support representative (SSR) or client to change various
boot-time options and for other limited service functions.
Concurrent maintenance
The IBM POWER7 processor-based systems are designed with the understanding that
certain components have higher intrinsic failure rates than others. The movement of fans,
power supplies, and physical storage devices naturally make them more susceptible to
wearing down or burning out. Other devices such as I/O adapters can begin to wear from
repeated plugging and unplugging. For these reasons, these devices have been specifically
designed to be concurrently maintainable when properly configured.
In other cases, a client might be in the process of moving or redesigning a data center or
planning a major upgrade. At times like these, flexibility is crucial. The IBM POWER7 and
POWER7+ processor-based systems are designed for redundant or concurrently
maintainable power, fans, physical storage, and I/O towers.
The most recent members of the IBM Power Systems family, based on the POWER7+
processor, continue to support concurrent maintenance of power, cooling, PCI adapters,
media devices, I/O drawers, GX adapter, and the operator panel. In addition, they support
guiding
Chapter 4. Continuous availability and manageability
the service
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