Cisco Systems UCS C420 manual Internal Diagnostic LEDs, LED Name State

Chapter 3 Maintaining the Server

Status LEDs and Buttons

Internal Diagnostic LEDs

The server is equipped with a supercap voltage source that can activate internal component fault LEDs up to 30 minutes after AC power is removed. The server has internal fault LEDs for fan modules, CPU sockets, DIMM sockets, the motherboard RTC battery, PCIe sockets, TPM socket, I/O riser socket, and SD cards.

To use these LEDs to identify a failed component, press the front or rear identification button with AC power removed (see Figure 3-1or Figure 3-2for the identification button location). See Figure 3-3for the locations of these internal LEDs.

Figure 3-3 Internal Diagnostic LED Locations

1 3 2 3 4

	DIMM L	DIMM G		PCle 7
FAN 1
	DIMM M	DIMM H
FAN 2	CPU 3	CPU 2	PCle 6
	DIMM K	DIMM F
FAN 3			PCle 5
	DIMM J	DIMM E
			PCle 4
	DIMM R	DIMM C
			PCle 3
FAN 4	DIMM S	DIMM D
			PCle 2
	CPU 4	CPU 1
FAN 5				PCle 2
	DIMM P	DIMM B
FAN 6
	DIMM N	DIMM A

2 8

5

6

7

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1	Fan module fault LEDs (one on each fan)	5	PCIe card fault LEDs (one for each PCIe
			socket on motherboard)
2	CPU fault LEDs on motherboard:	6	TPM fault LED on motherboard (CR40)
	• CPU1 LED = CR69
	• CPU2 LED = CR68
	• CPU3 LED = CR42
	• CPU4 LED = CR43
3	DIMM fault LEDs on motherboard (one for	7	I/O riser fault LED on motherboard (CR39)
	each DIMM socket)
4	RTC battery fault LED on motherboard	8	SD card fault LEDs on I/O riser

Table 3-3	Internal Diagnostic LED States
LED Name		State
Internal diagnostic LEDs (all)		•	Off—Component is functioning normally.
		•	Amber—Component has failed.

Cisco UCS C420 Server Installation and Service Guide

OL-27640-01 3-7