IBM Power 720 Overview page 185

and system locate LEDs will occur. These LEDs will turn on solid and can be used to follow
the light path from the system to the enclosure and down to the specific FRU.
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
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 positioned 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 locations 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 an LCD display (four rows by
sixteen 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 a service support representative (SSR) or client to
change various boot-time options and for other limited service functions.
Concurrent maintenance
The IBM POWER7 and 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 are
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 those times, 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
171