Sun Microsystems Ultra 1 140 Service Manual page 49

4.1.5 Symptom
4.1.6 Action
4.2 Power Supply Test
supply may be defective. See "Power Supply Test" below. If you hear a tone
and see lights on the keyboard, but the system still fails to initialize, see
Section 4.8, "System Board Test," on page 4-14.
No video output on the system monitor.
Check the power cord to be sure that it is connected to the monitor and to the
wall outlet. Verify that the wall outlet is supplying AC power to the monitor.
Check the video cable connection between the monitor and the system's
graphics card output port at the rear of the system. If the AC connection to the
monitor is correct and the video cable is correctly connected, the system
monitor or the system's internal graphics card may be defective. Replace the
monitor or the graphics card.
Use a VOM (volt-ohm-milliammeter) to check the power supply output
voltages. The power supply connectors J2601 and J2603 must remain connected
to the system board.
Place the VOM negative probe on one of the Gnd (ground) pins in the
connector, and test the +12v, -12v, +5v, +3.3v and +3.0v power pins
individually with the VOM positive probe.
See Table 4-1 and Table 4-2 for power supply connector pin descriptions.
Troubleshooting Procedures
4
4-3