Keysight Technologies N5247B, Service Manual

Page: 129 / 566

Keysight N5247B Service Guide 4-33
Troubleshooting
Measurement System Troubleshooting
— A14 frequency reference 1
— A4 and A17 (A17 optional on 2-port analyzers) 13.5 GHz source
synthesizers
1
— A5 and A10 (A10 optional on 2-port analyzers) sources
— A15 13.5 GHz LO synthesizer
2
(models with serial prefixes
<
6021
only)
— A15 direct digital synthesizer (DDS) assembly 2 (models with serial
prefixes ≥ 6021 or with version 7 synthesizer assembly upgrades only)
— A25 HMA26.5
3
— A26 splitter 3
— A70 and A75 Low Frequency Extension (LFE) board
— A23 test set motherboard
— the signal separation group
— A50, A51, A52, and A53 mechanical switches (optional)
— A54 combiner (optional)
— A29, A30, A31, and A32 reference couplers
— A38, A39, A40, and A41 60-dB source step attenuators (optional)
— A42, A43, A44, and A45 60-dB bias tees (optional)
— A71, A72, A73, or A74 bias combiner
— A33, A34, A35, and A36 test port couplers
— A23 test set motherboard
— the receiver group
— A37 reference mixer switch
— A46, A47, A48, and A49 35-dB receiver step attenuators (optional)
— A27 and A28 mixer bricks
— A16 SPAM board
— A24 IF multiplexer board
— A23 test set motherboard
Use the list on the following pages to help you determine in which analyzer
functional group to begin troubleshooting.
1. A4, A11, A10, A13, A21, A22 boards and components apply only to PNA models with
serial number prefixes
<
6021.
2. If your PNA has a serial prefix
≥
6021, then A15 is a direct digital synthesizer (DDS)
assembly. If your PNA has a serial prefix
<
6021, then A11 is a 13.5 GHz synthesizer
board.
3. Some PNAs have installed a legacy HMA26.5 (5087-7765) that is used with a dis-
crete A26 splitter. Some PNAs have installed a new HMA26.5 (N5240-60101) with
an integrated splitter. To identify which HMA26.5 is installed in your PNA, refer to
“Verify the Model/Version of HMA26.5 Installed” on page 4-41 .