Specifications

178 IBM Power 770 and 780 Technical Overview and Introduction
connection. Positive retention mechanisms such as latches, levers, thumb-screws, pop
Nylatches (U-clips), and cables are included to help prevent loose connections and aid in
installing (seating) parts correctly. These positive retention items do not require tools.
Light Path
The Light Path LED feature is for low-end systems, including Power Systems up to models
750 and 755, that can be repaired by clients. In the Light Path LED implementation, when a
fault condition is detected on the POWER7 processor-based system, an amber FRU fault
LED is illuminated, which is then rolled up to the system fault LED. The Light Path system
pinpoints the exact part by turning on the amber FRU fault LED that is associated with the
part to be replaced.
The system can clearly identify components for replacement by using specific
component-level LEDs, and can also guide the servicer directly to the component by
signaling (staying on solid) the system fault LED, enclosure fault LED, and the component
FRU fault LED.
After the repair, the LEDs shut off automatically if the problem is fixed.
Guiding Light
Midrange and high-end systems, including models 770 and 780 and later, are usually
repaired by IBM Support personnel.
The enclosure and system identify LEDs turn on solid and can be used to follow the path from
the system to the enclosure and down to the specific FRU.
Guiding Light uses a series of flashing LEDs, allowing a service provider to quickly and easily
identify the location of system components. Guiding Light can also handle multiple error
conditions simultaneously, which might be necessary in some very complex high-end
configurations.
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
guiding the service
representative to the correct rack, system, enclosure, drawer, and component.