IBM 2104 Model DU3 - Manual (Page 46)

3. Refer to Figure 23.
4. Ensure that the DC On/Standby switch 1 is set to Standby.
5. Ensure that all power is removed from the rack.
6. Plug the other end of the power cable into the power source in the rack (see
the Installation and Service Guide, or equivalent, for the rack).
7. Perform the grounding checks described in the Expandable Storage Plus: 2104
Models DU3 and TU3 Service Guide.
8. If the grounding check is satisfactory, switch on power to the rack. The green
AC PWR light 4 comes on.
9. Switch on the DC On/Standby switch 1 on each power supply. If option
switch 1 (see Figure 14 on page 19) is on, the green DC PWR light 3 comes
on. If option switch 1 (see Figure 14 on page 19) is off, the green DC PWR
light
3 stays off. It will come on when the 2104 is connected to the using
system.
10. Go to “Connecting the 2104 to the Using System” on page 31.
Figure 23. Check Power Supply Switch and Lights
30 2104 Model DU3 Installation Guide