Keysight N5227B, Service Manual

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Keysight N5227B Service Guide 4-45
Troubleshooting
Measurement System Troubleshooting
— Port 1; W82 of A38
— Port 2; W94 of A41
— Port 3; W86 of A39
— Port 4; W90 of A40
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 7-47 .
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 7-47 .
Checking the A50, A51, A52, and A53 Mechanical Switches
1. Locate the appropriate semirigid cable at the output of the mechanical
switch to be checked:
— Options 224 and 423
— Port 1; W106 of A50
— Port 2; W120 of A53
— Port 3; W112 of A51
— Port 4; W116 of A52
2. Using a 5/16-inch torque wrench, disconnect the semirigid cable at the
bypass switch.
3. Connect the spectrum analyzer to the open bypass switch connector. Set
the spectrum analyzer to measure a signal at 800 MHz.
4. If the 800 MHz signal is present, replace the associated receiver coupler.
Refer to “Removing and Replacing the A29 –A32 Receiver Couplers and
Receiver Coupler Mounting Brackets” on page 7-41 .
Checking the A70–A74 Bias Combiners
Refer to “Checking the A70/A75 Low Frequency Extension (LFE) Board and
the Bias Combiners” on page 4-40 .