Agilent Technologies N5230A, Service Manual, Page: 99 / 262

Service Guide N5230-90014 4-29
PNA Series Microwave Network Analyzers Troubleshooting
N5230A Measurement System Troubleshooting
• If all traces are present and are similar to the traces in Figure 4-9 , then there are no
major problems with the analyzer’s measurement system. There may, however, be a
minor failure in the analyzer.
To test further:
— Go to Chapter 3, “Tests and Adjustments” and perform all the tests in that section.
— If a problem still exists, contact Agilent. Refer to “Contacting Agilent” on page 2-11 .
• If any of the traces are not present, are noisy or distorted, or are at an incorrect level,
then there is a problem with the analyzer’s measurement system. Proceed to “Where to
Begin Troubleshooting.”
Where to Begin Troubleshooting
For the purposes of troubleshooting, the analyzer block diagram is divided into the
following functional groups:
• the source group
— A6 and A8 multipliers
— A7 and A9 fractional-N synthesizers
— A10 frequency reference
— A16 test set motherboard
— A19 SSLAM
• the signal separation group
— A19 SSLAM
— A25 and A26 60-dB step attenuators (Option 1E1 only)
— A21 and A22 test port couplers
— Port 1, Port 2, and A, B, R1, and R2 ports
• the receiver group
— A20 mixer brick
— A5 SPAM board
Use the list on the following pages to help you determine in which analyzer functional
group to begin troubleshooting.
This is by no means an exhaustive list of possible symptoms nor possible failures. It is
recommended that you view the system block diagram, at the end of this chapter, as you
review the entries in this list and perform any of the troubleshooting procedures listed.
Good judgement and established logical troubleshooting techniques must be used to
complement the procedures contained in this section.
Refer to Table 4-7 on page 4-39 for a list of the frequencies associated with each of the
network analyzer’s bands.
All Traces
• If all traces are missing in all bands , the problem is most likely in the source group.
However, a missing or disabled DSP driver may exhibit the same or similar symptoms.