IBM 3531 manual ESM board user controls

AC power connector

The power cord for the power supply connects here.

Power-supply/Fan CRU

The two hot-swap power supplies with built-in fans are located on the back of the expansion unit.

Attention: The EXP300 comes with two power-supply/fan units installed. When one power supply fails, the power-supply unit must be replaced to re- establish redundancy. When replacing the failed unit with the new power supply unit, ensure that this operation is performed in less than 10 minutes to prevent any overheating.

The fan that is visible from the rear of the power supply is an auxiliary fan that is normally off. This fan turns on only when the main fan within the power supply fails.

Power on/off switch

Use this switch to turn the power supply on and off.

Fault LED (amber)

When completely lit, this amber fault LED indicates a power supply failure or that a redundant power supply is not on. This LED also flashes when the built-in fan fails.

DC power LED (green)

This green LED is lit when the expansion unit is turned on and is supplying both 5 V and 12 V dc power.

AC power LED (green)

This green LED is lit when the expansion unit is receiving ac power.

Handles The two handles are used for installing and removing the power supply.

ESM board user controls

Two environmental services monitor (ESM) boards are accessible from the back of the expansion unit. These components contain several user controls, indicators, and connectors.

	SCSI Bus	Termination-	SCSI Bus
		power
Termination-	connector 2	LED (green)	connector 1
	LVD/SE	Push pin	LVD/SE
power
LED (green)	LED (green)		LED (green)
	Activity		Activity
ESM board	LED (green)		LED (green)

Push pin

ESM board

7

6

0 1

2

5

SCSI reset	Fault	SCSI reset	Fault
LED (green)	LED (amber)	LED (green)	LED (amber)

ESM board The environmental services monitor (ESM) boards contain the SCSI controls and LEDs.

16IBM Netfinity EXP300 - Type 3531 Hardware Maintenance Manual