Sun Microsystems Ultra 5, Service Manual

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Chapter 4 Troubleshooting Procedures 4-5
■
If the hard drive responds correctly to
probe-ide
command, the message shown
in
CODE EXAMPLE 4-4
on page 4-10 is displayed, which means that the system
EIDE controller has successfully probed the device. This is an indication that the
motherboard is operating correctly.
■
If an optional hard drive is installed and one drive does not respond to the EIDE
controller probe but the other does, replace the unresponsive drive.
■
If the
probe-ide
test fails to show the device in the message, replace the drive
(see ). If replacing the hard drive does not correct the problem, replace the
motherboard.
4.4 Power Supply Test
The section describes how to test the power supply.
FIGURE 4-1
and
TABLE 4-2
describe
power supply connector J17.
1. Power off the system, remove the system cover, and attach an antistatic wrist strap
as described in Chapter 5.
2. Remove the PCI card from riser board connector 2 (adjacent to the power supply),
if necessary for clearance. Disconnect the ribbon cables from the motherboard to
expose connectors J17.
3. Power on the system.
See Section 10.2 “Powering On the System” on page 10-2.
Caution –
With the system cover removed and the system powered on, there is
unprotected access to voltage and energy levels that are potentially hazardous to
equipment and personnel. If you are unsure how to safely proceed, please seek the
assistance of qualified service personnel.
4. Using a digital voltage meter (DVM), check the power supply output voltages as
follows:
Note – Power supply connector J17 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
.
5. If any power pin signal is not present with the power supply active and properly
connected to the motherboard, replace the power supply.