LSI 8751D - Manual (Page 26)

2-10 Installing the LSI8751D
Step 4. Most PC cabinets are designed with a front panel LED, which
may already be connected to an existing IDE drive. Connect
this LED cable to connector J4 on the host adapter, as shown
in
Figure 2.8 . This allows the front panel LED to indicate activity
on the SCSI bus. Connector J4 is not keyed. The orientation of
the LED cable does not matter as long as all four pins are
connected.
Figure 2.8 SCSI LED Connector
Some LED cables have only two wires. In this case, place the
connector on one end or the other of J4. If the LED does not light
during SCSI bus activity from this host adapter, you may have to
rotate the LED cable 180
° on J4.
Connector J4