Power Supply Trouble Isolation - Keysight 9000 Series Service Manual

Chapter 4: Troubleshooting

Power Supply Trouble Isolation

Power Supply Trouble Isolation
W A R N I N G
SHOCK HAZARD!
Only trained service personnel who are aware of the hazards involved should perform the maintenance.
Read the safety summary at the back of this book before proceeding. Failure to observe safety
precautions may result in electric shock.
For information on how to replace assemblies, see "Replacing Assemblies," beginning on page 81.
These trouble isolation instructions help isolate the problem to the assembly level when the power system
is not operating. Because of advanced power system protection features, the problem may not be with
the supply itself and, therefore, you will need to use the LEDs located in the upper right corner of the
acquisition board to determine the fault. These LEDs can be seen by looking through the rear fan slots
in the upper right corner as viewed from the rear of the oscilloscope. After a shutdown occurs, keep the
power cord plugged in so the LEDs remain illuminated. Once you have noted the LED pattern, you can
unplug the instrument.
If the oscilloscope still will not power on after you have followed the required steps below, refer to the
Motherboard Verification section in this chapter for additional diagnosis suggestions.
60
Look through these
slots and the fans
located behind them
to see the upper
right corner of the
acquisition board