IBM 88554RU Installation Guide - Page 42

diagnostics monitored server subsystems. In the event that maintenance is required the customer can slide the server out from the rack and, using the LEDs, find the failed or failing component. As illustrated in Figure 1-15, light path diagnostics are able to monitor and report on the health of CPUs, main memory, hard disk drives, PCI-X slots, fans, power supplies, power modules and the internal system temperature. FAN 1 2 SUPPOPWLYER PCDI ABMSUDESCMPOURY TEMP REMINODVNEROVNSRPRMEECDEVEBNOTNAMRLODI G i ! CPU MEMORY Light Path Diagnostics™ DASD PCI-X BUS NMI BOARD FAN TEMP EVENT LOG 1 POWER 2 SUPPLY VRM NON REDUND OVER SPEC REMIND Figure 1-15 Light path diagnostics panel on the x455 Important: If a light path diagnostics LED has been illuminated and system power is removed, there is no way to redisplay the LEDs on the system tray without re-applying AC power. If the fault has not been rectified when power is restored, the LED will re-light. The light path diagnostics on the x455 has four levels: The first level is the front panel fault LED. Level 2 is the pop-out panel, as shown in Figure 1-15. For further investigation, there are light path diagnostics LEDs visible through the top of the server. This requires the server to be slid out of the rack. For the fourth level of diagnostics, LEDs on major system components indicate the component causing the error. As the processor-board assembly is not visible during normal operation, a light path diagnostics button has been incorporated into it to assist with diagnosing errors. You can light up the LEDs for a maximum of two minutes. After that time, the circuit that powers the lights is exhausted. 28 IBM xSeries 455 Planning and Installation Guide Eserver