Service manual

4-4 Sun Ultra 2 Series Service Manual • July 1996
● At the system prompt, type:
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 others do, replace the unresponsive drive.
If one internal disk drive is configured with the system and the probe-scsi test
fails to show the device in the message, replace the drive. If the problem is still
evident after replacing the drive, replace the motherboard. If replacing both the hard
drive and the motherboard does not correct the problem, replace the internal disk
drive cable and SCSI backplane assembly.
4.4 Power Supply Test
The following provides instructions to test the power supply.
FIGURE 4-1 and TABLE 4-2 identify power supply connector J3203. FIGURE 4-2 and
TABLE 4-3 identify power supply connector J3204. FIGURE 4-3 and TABLE 4-4 identify
power supply connector J3205.
FIGURE 4-4 and TABLE 4-5 identify power supply
connector J3206.
1. Using a volt-ohm-milliammeter (VOM), check the power supply output voltages
as follows:
Note – Power supply connectors J3203 through J3206 must remain connected to the
motherboard.
2. With the negative probe of the VOM meter placed on the ground (Gnd) pin,
position the positive probe on each power pin.
3. Verify +12 VDC, -12 VDC, +5 VDC, +3.3 VDC and +3.0 VDC.
4. If any power pin signal is not present with the power supply active and properly
connected to the motherboard, replace the power supply.
Note – Pins listed in the following tables are referenced to the motherboard bottom
view.
ok reset-all
ok probe-scsi