Sun Microsystems 60 service manual Power Supply Test

If the hard drive responds correctly to probe-scsi, the message identified in CODE EXAMPLE 4-4is displayed. If the drives respond and a message is displayed, the system SCSI controller has successfully probed the devices. This is an indication that the motherboard is operating correctly. If one drive does not respond to the SCSI controller probe but the other does, replace the unresponsive drive. If one hard drive is configured with the system and the probe-scsitest fails to show the device in the message, replace the drive. If the problem is still evident after replacing the hard drive, replace the SCSI drive bay (see Section 8.3, “Hard Drive Bay With SCSI Assembly” on page 8-7) If replacing both the hard drive and the SCSI drive bay does not correct the problem, replace the motherboard.

4.4Power Supply Test

The section describes how to test the power supply. FIGURE 4-1and TABLE 4-2identify power supply connector J2901. FIGURE 4-2and TABLE 4-3identify power supply connector J2902. FIGURE 4-3and TABLE 4-4identify power supply connector J2903.

1.Power off the system.

2.Remove the side access cover.

See Section 7.1, “Removing the Side Access Cover” on page 7-2.

3.Slide the power supply from the chassis enough to expose connectors J2901 through J2903.

4.Power on the system.

5.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 TABLE 4-2, TABLE 4-3, and

TABLE 4-4.

6.If any power pin signal is not present with the power supply active and properly connected to the motherboard, replace the power supply.

Chapter 4 Troubleshooting Procedures 4-5