Technical data

4-28 Service Guide N5230-90025
Troubleshooting PNA Series Microwave Network Analyzers
Measurement System Troubleshooting N5230C
Where to Begin Troubleshooting
For the purposes of troubleshooting, the analyzer block diagram is divided into the following functional
groups:
• the source group
— A6, A8, and A12 (Options 146 and 246 only) multipliers
— A7, A9, and A13 (Options 146 and 246 only) fractional-N synthesizers
— A10 frequency reference
— A16 test set motherboard
— A17 QABC board (Options 146 and 246 only)
— A18 MASS 26.5 (MASSQuad) (Options 146 and 246 only)
— A19 MASS 26.5 (MASSQuad)
• the signal separation group
— A18 MASS 26.5 (MASSQuad) (Options 146 and 246 only)
— A19 MASS 26.5 (MASSQuad)
— A21, A22, A23, and A24 test port couplers
— A25 60-dB step attenuator (Options 145, 245, 146, and 246 only)
— A26 60-dB step attenuator (Options 146 and 246 only)
— Port 1, Port 2, Port 3, Port 4, and A, B, C, D, and R ports
• the receiver group
—A5 SPAM board
—A20 mixer brick
— A29 reference channel switch (Options 146 and 246 only)
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 4-4 on page 4-33 for a list of the frequencies associated with each of the network analyzer’s
13 or 17 bands.