Keysight Technologies N5221A, Service Manual, Page: 113 / 368

Keysight N5221A/22A Service Guide 4-39
Troubleshooting
Measurement System Troubleshooting
Checking the Signal Separation Group
Before checking the signal separation group assemblies, you must open the
analyzer.
1. Turn off the analyzer power.
2. Unplug the power to the analyzer and disconnect all front and rear panel
connections except installed jumpers.
3. Remove the outer cover from the analyzer. Refer to “Removing the Covers”
on page 7-6 .
4. With the covers off, plug in the analyzer and turn on the power.
Checking the Output Power of the A, B, C, and D Signals
Using a power meter, you can measure the outputs of the A, B, C, and D
signals from the front panel. The measurement results will help you isolate a
faulty assembly. The output of the R receiver cannot be measured because it
would necessitate breaking the phase lock loop, causing all of the signals to be
lost.
Equipment Used for This Check
Equipment Setup
1. Before starting these checks, zero and calibrate the power meter. (See the
power meter user’s guide for instructions on setting the calibration factor.)
Use an antistatic work surface and wrist strap to reduce the chance of
electrostatic discharge for all of the procedures in this chapter.
Procedures described in this document are performed with power
supplied to the product while protective covers are removed. Energy
available at many points may, if contacted, result in personal injury.
Do not operate the analyzer with the outer cover removed for more than
30 minutes, as this could cause the analyzer to overheat which could
result in costly damage.
Equipment Type Model or
Part Number
Alternate Model or
Part Number
Power meter E4418B/E441B E4418A/E4419A
Power sensor, 3.5 mm E8485A None
Adapter, 3.5 mm (f) to 3.5 mm (f) 83059B 85052-60012