Keysight N5227B, Service Manual

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Keysight N5227B Service Guide 4-43
Troubleshooting
Measurement System Troubleshooting
4. The measured output power on the power meter should be at least the
preset power level ±1 dB over the entire frequency range.
— If the measured power is correct, go to “Checking the Receiver
Group” on page 4-46 .
— If the measured power is not correct, go to “Checking the Signal
through the Signal Separation Path” on page 4-43 .
Checking the Signal through the Signal Separation Path
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 6-23
— “2-Port Configuration, Option 205” on page 6-36
— “2-Port Configuration, Option 210” on page 6-43
— “2-Port Configuration, Option 219” on page 6-49
— “2-Port Configuration, Option 220” on page 6-56
— “4-Port Configuration, Option 400” on page 6-63
— “4-Port Configuration, Option 401” on page 6-70
— “4-Port Configuration, Option 405” on page 6-77
— “4-Port Configuration, Option 410” on page 6-86
— “4-Port Configuration, Option 419” on page 6-93
— “4-Port Configuration, Option 420” on page 6-105
Trace loss in the signal separation group is due to one or more of the following
assemblies being defective:
— A50, A51, A52, or A53 mechanical switch and A54 combiner (A54 is only
available in 4-port models with Option 423 and 2-port models with Option
224.)
— A29, A30, A31, or A32 receiver coupler
— A38, A39, A40, or A41 source step attenuator
— A42, A43, A44, or A45 bias tee
— A33, A34, A35, and A36 test port coupler
— A71, A72, A73, and A74 bias tee combiners
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
, S
22,
S
33,
or S
44,
measurement for Port 1, 2,
3, or 4 respectively, with a CW frequency of 800 MHz.
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.