Checking The Source Group - Agilent Technologies PNA Series Service Manual

PNA Series Microwave Network Analyzers
E8361A

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 A8, A9, A10, A11, A12, or A16 board
have been replaced with newer board assemblies.
1
Board Assembly
A12 source 20
A10 frequency reference
A11 phase lock
A8 fractional-N synthesizer
A16 test set motherboard, MA 20
A16 test set motherboard, SOMA 50
A16 test set motherboard, AUX 1
A16 test set motherboard, AUX 2
A9 fractional-N synthesizer (Option 080 only)
1. Board assembly A9 troubleshooting is discussed further in the
the Frequency Offset Group (Option 080)" on page
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 menu, point to
System
• The dialog box in
Service Guide E8361-90001
Service,
Figure 4-10 on page 4-36
Measurement System Troubleshooting
Node Numbers
111 to 118
211 to 218
311 to 318
411 to 418
511 to 518
611 to 618
711 to 718
811 to 818
911 to 918
4-54.
and then click
Serial Bus Test
is displayed. Click
Troubleshooting
"Checking
.
to start the test.
Begin
4- 35