Power-On Does Not Succeed; Power Supply Test - Sun Microsystems SPARCclassic Service Manual

Use a VOM to perform the continuity test on the video cable.
If the power cord and video cable connection are good and there is still no video
output, reseat the video card for the monitor.
4. If the monitor power supply is internally fused, check the fuse.
The fuse could be blown.

Power-On Does Not Succeed

1. Turn off the system power switch.
2. Check that the system power cord is properly connected to the system rear
panel power receptacle and to the wall outlet.
3. Verify with a VOM that the wall outlet is supplying AC power to the system.
4. Turn the system power switch on and observe the keyboard.
The LEDs on the keyboard should briefly light. You should hear a tone from the
keyboard.
If you hear no tone or see no lights on the keyboard, the system's power supply
may be defective. See "Power Supply Test" on page 33.
If you hear a tone and see lights on the keyboard, but the system still fails to
initialize, see "System Board Test" on page 35.
5. If the system power supply is internally fused, check the fuse.
The fuse could be blown. If the power supply is working, you should hear the
fans humming.

Power Supply Test

1. Use a VOM (Volt Ohmmeter) to check the power supply output voltages.
Place the VOM negative probe on one of the logic ground pins in the connector,
and test the +12V, –12V, and +5.1V power pins individually with the positive
probe (pins 1 through 7). See Figure 4–1.
Troubleshooting Procedures
33