192 Chapter 9 I/O Ports and Connectors
Fan Connectors

These connectors are identical.

Pin Signal
1 GND (ground)
2 Fan sense
3 +12 V
Blower Connectors

These connectors are identical.

Pin Signal
1 Boost
2 GND (ground)
3 Tachometer
4 +12 V
SCSI Controller Activity LED Connector
Pin Signal
1 Return
2 Hard disk active
3 Hard disk active
4 Return