Agilent Technologies Infiniium 90000 A Service Manual page 59

Chapter 4: Troubleshooting
Power Supply Trouble Isolation
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 work through the
procedure systematically to determine the source of the fault. There are three main types of
faults: under-voltage faults (a defective power supply is included in this section), over-
temperature faults, and over-voltage faults. The following sections will describe each of these
faults in detail so you can deduce the reason for your power failure and fix the problem.
The flowchart above also walks you through the diagnostic steps and points you to the correct
sections for further details.
If the oscilloscope still will not power on after you have followed the required steps in this
Power Supply Trouble Isolation section, refer to the Motherboard Verification section in this
chapter for additional diagnosis suggestions.
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