4-26 Service Guide N5230-90014
Troubleshooting PNA Series Microwave Network Analyzers
Measurement System Troubleshooting N5230A
Measurement System Troubleshooting
This section provides troubleshooting procedures for the measurement portion of the PNA 
series network analyzer. In this section, the analyzer is used as a tool to help isolate the 
suspected faulty functional group. Once the faulty functional group is determined, 
troubleshooting steps are provided to help you isolate the faulty assembly or part.
Before you begin—consider: Where do you see a problem?
If you are seeing a problem at Preset, perform the standard S-parameter test set 
troubleshooting procedure, starting with: “Verifying the A, B, R1, and R2 Traces (Standard 
S-Parameter Mode)” on page 4-28.
You should also consider the problem indications that are observed and whether the 
observed condition is a soft failure or a hard failure.
Soft Failure
With a soft failure, the network analyzer's performance has degraded to an unacceptable 
level, yet it continues to operate and displays no error messages. For this type of failure, 
performance tests must be conducted to isolate the problem. Begin with viewing the error 
terms as described in “Error Terms” in Chapter 8  This will help to isolate most problems. 
If additional tests are required, refer to “Performance Tests (Agilent N7840A Software 
Package)” on page 3-28.
Hard Failure
With a hard failure, the PNA does not perform well and displays one or more error 
messages. To diagnose and repair a hard failure:
•Check “Help About” to verify that the model number and options listed match the 
actual analyzer model and options.
•Check “EEPROM Headers” to verify that the data there is correct.
• Check error messages. Refer to “Error Messages” and follow the suggestions outlined 
there for each applicable error message.
Help About
Go to the Help About screen by selecting 
Help, About Network Analyzer in the network 
analyzer application. Verify that the information displayed in this screen is correct for your 
analyzer. If any of the information is incorrect, contact Agilent Technologies. Refer to 
“Contacting Agilent” on page 2-11.