Service manual

4-2 Sun Ultra 2 Series Service Manual July 1996
the system unit powers on, no further action is required. If the system unit does not
power on, the keyboard may be defective. Connect a spare Sun Type-5 keyboard to
the system unit and press the Power-on key.
If the wall receptacle AC power has been verified, the CPU module is properly
seated, and a spare Sun Type-5 keyboard has been connected to the system unit and
the Power-on key has been pressed but the system unit does not power up, the
system unit power supply may be defective. See Section 4.4 “Power Supply Test” on
page 4-4.
Symptom
The system unit attempts to power up but does not boot or initialize the monitor.
Action
Press the keyboard Power-on key and watch the keyboard. The keyboard LEDs
should light briefly and a tone from the keyboard should be heard. If a tone is not
heard or if the keyboard LEDs do not light briefly, the system unit power supply
may be defective. See Section 4.4 “Power Supply Test” on page 4-4. If a keyboard
tone is heard and the keyboard LEDs light briefly but the system unit still fails to
initialize, see Section 3.9 “Initializing the Motherboard POST” on page 3-15.
4.2 Video Output Failure
This section provides video output failure symptom and suggested action.
Symptom
No video at the system monitor.
Action
Check the monitor AC power cord. Ensure that the AC power cord is connected to
the monitor and to the wall receptacle. Verify that the wall receptacle is supplying
AC power to the monitor. Check the video cable connection between the monitor
and the system graphics card output port at the rear of the system. Check that the
CPU module is properly seated. If the AC connection to the monitor is correct, the
video cable is correctly connected, and the CPU module is properly seated, the
system monitor or the system graphics card may be defective. Replace the monitor
or the graphics card.