Service Guide N5230-90014 4-31
PNA Series Microwave Network Analyzers      Troubleshooting
N5230A Measurement System Troubleshooting
Checking the Source Group
Serial Bus Test
Before performing tests on specific assemblies in the source group, it is recommended that 
you perform the serial bus test. This may help to isolate the failure to a specific assembly.
Through the front panel, the serial bus test allows you to check signal and voltage levels at 
32 points (nodes) distributed across four of the printed circuit board assemblies in the 
analyzer. With this test you can isolate problem board assemblies in the analyzer. The 
board assemblies tested and their associated node numbers are as follows:
NOTE
This test is written for a PNA series network analyzer as it was originally 
shipped from the factory. Due to changes in board production, this test may 
not show accurate pass/fail results if the A6, A7, A8, A9, A10, or A16 board 
have been replaced with newer board assemblies.
Descriptions of each board assembly and node is included in this section. Location of the 
nodes is indicated with a ♦ symbol on the block diagrams located at the end of this chapter.
Performing the Serial Bus Test
First, this test sequentially checks all 48 nodes at 45 MHz. Next, the test checks all nodes 
that change values with frequency, at 49 different frequency points. For each node, 
measured values are copied to an ASCII text file in the service directory on the hard disk 
drive. Any measured values that exceed the tolerances are highlighted in the application 
and the data file.
To run the serial bus test:
•On the 
System menu, point to Service, and then click Serial Bus Test.
• The dialog box in Figure 4-10 on page 4-32 is displayed. Click 
Begin to start the test.
Board Assembly Node Numbers
A6 multiplier 1211 to 1218
A8 multiplier 1111 to 1118
A10 frequency reference 211 to 218
A7 fractional-N synthesizer 411 to 418 
A16 test set motherboard, MA 511 to 518 
A16 test set motherboard, SSLAM 611 to 618 
A16 test set motherboard, AUX 1 711 to 718 
A16 test set motherboard, AUX 2 811 to 818 
A9 fractional-N synthesizer 911 to 918