Keysight Technologies N5247B, Service Manual

Page: 146 / 566

4-50 Keysight N5247B Service Guide
Troubleshooting
Measurement System Troubleshooting
4-
Equipment Used for These Tests
To determine which assembly is defective, check the signal at each available
measurement point in the signal path from the output of the source board to
the output port.
Set the network analyzer for an S
11, S22, S33, or S44,
measurement for Port 1, 2,
3, or 4 respectively, with a CW frequency of 800 MHz.
Perform the following checks in the order presented.
Checking the A29, A30, A31, and A32 Reference Couplers
1. Locate the appropriate semirigid cable at the output of the reference
coupler to be checked:
— Options 201 and 400
— Port 1; W19 of A29
— Port 2; W31 of A32
— Port 3; W23 of A30
— Port 4; W27 of A31
— Options 219, 224, 419, and 423
— Port 1; W81 of A29
— Port 2; W93 of A32
— Port 3; W85 of A30
— Port 4; W89 of A31
2. Using a 5/16-
torque wrench, disconnect the semirigid cable at the reference coupler.
3. Connect the spectrum analyzer to the open reference coupler connector.
Set the spectrum analyzer to measure a signal at 800 MHz.
4. If the 800 MHz signal is not present and the analyzer has mechanical
switches, continue testing at “Checking the A50, A51, A52, and A53
Mechanical Switches” on page 4-51 .
5. If the 800 MHz signal is not present and the analyzer does not have
mechanical switches, replace the reference coupler. Refer to “Removing
and Replacing the A29 –A32 Reference Couplers and Reference Coupler
Mounting Brackets” on page 7-43 .
Equipment Type Model or
Part Number
Alternate Model or Part
Number
Spectrum analyzer 8565E
856xE
a
a. Must be capable of measuring a signal at 1 GHz.