Keysight N5224A/25A Service Guide 4-43
Troubleshooting
Measurement System Troubleshooting
6.
If the 800 MHz signal is present and the analyzer does not have source
attenuators and bias tees, replace the test port coupler. Refer to
“Removing and Replacing the A33–A36 Test Port Couplers” on page 7-40
.
Checking the A38, A39, A40, and A41 60-dB Source Step Attenuators
1.
Locate the appropriate semirigid cable at the output of the source step
attenuator to be checked:
—
Options 219 and 419
—
Port 1; W82 of A38
—
Port 2; W94 of A41
—
Port 3; W86 of A39
—
Port 4; W90 of A36
2.
Using a 5/16-inch torque wrench, disconnect the semirigid cable at the
step attenuator.
3.
Connect the spectrum analyzer to the open step attenuator connector. Set
the spectrum analyzer to measure a signal at 800 MHz.
4.
If the 800 MHz signal is not present, replace the source step attenuator.
Refer to
“Removing and Replacing the A38–A41 Source Attenuators and
the A46–A49 Receiver Attenuators” on page 7-45
5.
If the 800 MHz signal is present, replace the associated bias tee. Refer to
“Removing and Replacing the A38–A41 Source Attenuators and the A46–
A49 Receiver Attenuators” on page 7-45
Checking the Receiver Group
Equipment Used for These Tests
For all of the following checks, refer to the block diagrams at the end of this
chapter and to any of the following that are appropriate:
—
“2-Port Configuration, Option 200” on page 6-22
—
“Bottom RF Cables, Standard 2-Port Configuration, Option 200” on
—
“2-Port Configuration, Option 219” on page 6-47
—
“Bottom RF Cables, 2-Port, Option 219” on page 6-49
—
“4-Port Configuration, Option 400” on page 6-54
Equipment Type
Model or
Part Number
Alternate Model or Part
Number
Spectrum analyzer
8565E
856xE
a
a. Refer to . Must be capable of measuring a signal at 7.61 MHz (analyzers with DSP version 4.0), or
7.44 MHz (analyzers with DSP version 5.0), and 1 GHz.