Sun Microsystems Netra t 1120, Service Manual

Page: 53 / 148

Chapter 4 Troubleshooting Procedures 4-5
4.3 Power Supply Test
This section describes how to test the power supply.
FIGURE 4-1
and
TABLE 4-2
identify power supply connector J2901.
FIGURE 4-2
and
TABLE 4-3
identify power
supply connector J2902.
FIGURE 4-3
and
TABLE 4-4
identify power supply connector
J2903.
1. Attach a wrist strap.
See Section 7.1 “To Attach the Wrist Strap” on page 7-1.
2. Power off the system and remove the power cord(s).
See Section 6.2 “To Power Off the System” on page 6-3.
3. Remove the top access cover.
See Section 7.2 “To Remove the Top Access Cover” on page 7-4.
4. Follow Step 4 to Step 9 in Section 8.1.1 “To Remove the Power Supply” on
page 8-1.
5. Lift the power supply from the chassis until it is restrained by the power supply
cables. Rest the power supply on the front crossmember of the enclosure to
expose connectors J2901 through J2903.
6. Reconnect the input power connector(s) and power on the system.
See Section 6.1 “To Power On the System” on page 6-2.
7. Using a digital voltage meter (DVM), check the power supply output voltages as
follows:
Note –
Power supply connectors J2901 through J2903 must remain connected to the
motherboard.
a. With the negative probe of the DVM placed on a connector ground (Gnd) pin,
position the positive probe on each power pin.
b. Verify voltage and signal availability as listed in the tables below.