Anritsu 371 C Series User manual

MODEL
371XXC
VECTOR NETWORK ANALYZER
MAINTENANCE MANUAL
P/N: 10410-00236
REVISION: B
PRINTED: SEPTEMBER 2002
COPYRIGHT: 2002 ANRITSU CO.
490 JARVIS DRIVE lMORGAN HILL, CA 95037-2809

WARRANTY
The ANRITSU product(s) listed on the title page is (are) warranted against defects in materials and
workmanship for three years from the date of shipment.
ANRITSU’s obligation covers repairing or replacing products which prove to be defective during the
warranty period. Buyers shall prepay transportation charges for equipment returned to ANRITSU
for warranty repairs. Obligation is limited to the original purchaser. ANRITSU is not liable for con-
sequential damages.
LIMITATION OF WARRANTY
The foregoing warranty does not apply to ANRITSU connectors that have failed due to normal wear.
Also, the warranty does not apply to defects resulting from improper or inadequate maintenance by
the Buyer, unauthorized modification or misuse, or operation outside of the environmental specifi-
cations of the product. No other warranty is expressed or implied, and the remedies provided herein
are the Buyer’s sole and exclusive remedies.
TRADEMARK ACKNOWLEDGEMENTS
V Connector and K Connector are registered trademarks of ANRITSU Company.
Ink Jet and Think Jet are registered trademarks of Hewlett-Packard Co.
MS-DOS and Windows are a registered trademarks of Microsoft Corporation.
Acrobat is a registered trademark of Adobe Corporation
NOTICE
ANRITSU Company has prepared this manual for use by ANRITSU Company personnel and cus-
tomers as a guide for the proper installation, operation and maintenance of ANRITSU Company
equipment and computer programs. The drawings, specifications, and information contained herein
are the property of ANRITSU Company, and any unauthorized use or disclosure of these drawings,
specifications, and information is prohibited; they shall not be reproduced, copied, or used in whole
or in part as the basis for manufacture or sale of the equipment or software programs without the
prior written consent of WILTRON Company.

Table of Contents
Chapter 1 — General Service Information
This chapter provides a general description of Series 371XXC Vector Network Analyzer systems, sys-
tem serial numbers, and frequency ranges. It explains the level of maintenance covered in this man-
ual and the service strategy used throughout this manual. It also contains static-sensitive component
handling precautions and a list of recommended test equipment.
Chapter 2 — Replaceable Parts
This chapter lists all replaceable subassemblies and components for all 371XXC models. It explains
the ANRITSU exchange assembly program and provides parts ordering information.
Chapter 3 — Operational Tests
This chapter contains procedures that provide a means of fully testing the 371XXC VNA system for
proper operation and signal stability. These tests are intended to be used as a periodic check of the
operational functionality of the 371XXC.
Chapter 4 — Performance Verification Procedures
This chapter provides detailed procedures for verifying that the performance of the 371XXC meets
minimum performance standards.
Chapter 5 — Troubleshooting
This chapter provides information for troubleshooting Series 371XXC Vector Network Analyzer sys-
tems. The troubleshooting procedures contained in this chapter support fault isolation down to a re-
placeable subassembly.
Chapter 6 — Adjustments
This chapter provides adjustment procedures for all models of Series 371XXC Vector Network Ana-
lyzer systems. These procedures are used after replacement or repair of one or more critical subas-
semblies, or as indicated by the Performance Verification Procedures contained in Chapter 4.
Chapter 7 — System Description
This chapter provides descriptions of the functional operation of the major assemblies contained in
Series 371XXC Vector Network Analyzer systems. The operation of all major circuit blocks is de-
scribed so that the reader may better understand the function of each assembly as part of the overall
operation.
Chapter 8 — Removal and Replacement Procedures
This chapter describes how to gain access to all of the major assemblies and major parts for
troubleshooting and/or replacement.
Appendix A — Diagnostic Menus
This appendix contains descriptions and usage information for the Diagnostic Menus that are avail-
able via the front panel Option Menu key.
371XXC MM i

Appendix B — Error Codes/Messages
This appendix contains a listing of the Error Codes/Messages. Also included is a description of the in-
formation fields that are part of the error messages.
Appendix C — Connector Maintenance Check Procedures
This appendix contains procedures and information needed to perform maintenance checks (includ-
ing pin-depth measurements) for the connectors on all ANRITSU supplied Calibration/Verification
Kit components, Through-cables, and other associated RF/microwave components.
Appendix D — Performance Specifications
Appendix E — Millimeter Wave Instructions
This appendix provides service instructions for the 371XXC Millimeter Wave System. The informa-
tion is specific to the 371XXC and is intended to supplement the common service instructions con-
tained in the other parts of this manual.
Appendix F — SM5235 and SM5392 Instructions
This appendix contains operation, specification, and adjustment information for the SM5235 and
SM5392 S-Parameter test sets.
Index
ii 371XXC MM

Table of Contents
Chapter 1 General Information
1-1 SCOPE OF MANUAL ·······················1-3
1-2 INTRODUCTION ·························1-3
1-3 ONLINE MANUALS ·······················1-3
1-4 IDENTIFICATION NUMBER ··················1-3
1-5 SYSTEM DESCRIPTION ·····················1-4
1-6 RELATED MANUALS·······················1-4
1-7 OPTIONS ·····························1-4
1-8 SERVICE STRATEGY·······················1-4
Functional Assembly Level Troubleshooting ·········1-5
Internal Hardware Adjustments and Calibrations ······1-5
Internal Service Log ······················1-5
System Test/ Certification ···················1-5
Preventive Service ·······················1-6
Servicing Specially Modified Instruments ··········1-6
1-9 SERVICE SUPPORT INFORMATION ··············1-6
Technical Support ·······················1-6
Service Software ························1-7
Test Fixtures/ Aids ·······················1-7
Failed Assembly Exchange Program ·············1-7
1-10 RECOMMENDED TEST EQUIPMENT ·············1-8
1-11 STATIC SENSITIVE COMPONENT
HANDLING PROCEDURES ···················1-9
1-12 SERVICE CENTERS ·······················1-9
1-13 PERFORMANCE SPECIFICATIONS ··············1-9
Chapter 2 Replaceable Parts
2-1 INTRODUCTION ·························2-3
2-2 EXCHANGE ASSEMBLY PROGRAM ··············2-3
2-3 REPLACEABLE SUBASSEMBLIES AND PARTS ·······2-3
2-4 PARTS ORDERING INFORMATION ··············2-4
371XXC MM iii

Chapter 3 Operational Tests
3-1 INTRODUCTION ·························3-3
3-2 CHECKING THE SERVICE LOG ················3-4
3-3 SELF TEST ····························3-5
3-4 PERIPHERALS AND INTERFACES TESTS ··········3-6
Display Test···························3-6
Front Panel Test ························3-7
External Keyboard Interface Test ···············3-7
Printer Interface Test ·····················3-7
GPIB Interface Test ······················3-9
Chapter 4 Performance Verification
4-1 INTRODUCTION ·························4-3
4-2 CALIBRATION AND MEASUREMENT CONDITIONS ····4-3
Standard Conditions ······················4-3
Special Precautions·······················4-4
4-3 PERFORMANCE VERIFICATION PROCEDURE ·······4-4
Noise Floor/Receiver Dynamic Range Test ··········4-5
Compression Test for 37147C, 37169C ············4-9
Chapter 5 Troubleshooting
5-1 INTRODUCTION ·························5-3
5-2 ASSOCIATED INFORMATION IN THIS MANUAL ······5-4
5-3 RECOMMENDED TEST EQUIPMENT ·············5-4
5-4 IF SYSTEM DOES NOT POWER-UP ··············5-4
Line Source and Interface Checks···············5-4
Power Supply Voltages Check ·················5-4
Power Supply Module Check··················5-6
5-5 IF SYSTEM DOES NOT BOOT-UP················5-7
Boot-up Process Sequence ···················5-7
Troubleshooting Boot-up Problems ··············5-8
Hard Disk Problem 1 ·····················5-8
Hard Disk Problem 2······················5-9
Floppy Disk Problems ·····················5-9
Screen Display Problems····················5-9
iv 371XXC MM

5-6 IF SYSTEM PRODUCES AN ERROR CODE··········5-10
Phase Lock Error Codes (6000 Series) ············5-11
Service Log Snap Shot Data ·················5-13
5-7 SIGNAL SOURCE, TEST SET, AND RECEIVER PROBLEMS 5-13
Signal Source Phase Lock Loop Assemblies ·········5-14
Signal Source/Test Set Module Error Codes ·········5-14
Isolation Procedures ·····················5-16
5-8 IF A PERIPHERALS/ INTERFACE TEST FAILED ······5-18
LCD Display Test Failures:··················5-18
Front Panel Test Failures: ··················5-18
External Keyboard Interface Test Failures: ·········5-18
Printer Interface Test Failures: ···············5-19
GPIB Interface Test Failures: ················5-19
5-9 IF MEASUREMENTS ARE IN QUESTION ··········5-19
Measurement Conditions Check List ············5-19
Chapter 6 Adjustments
6-1 INTRODUCTION ·························6-3
6-2 LO1 CALIBRATION························6-3
Calibration Procedure ·····················6-3
Post Calibration Actions ····················6-4
6-3 LO 2 CALIBRATION ·······················6-4
Calibration Procedure ·····················6-4
Post Calibration Actions ····················6-5
6-4 FREQUENCY CALIBRATION ··················6-5
Calibration Procedure ·····················6-6
Post Calibration Actions ····················6-7
6-5 RF POWER/ALC CALIBRATION·················6-8
Calibration Procedure ·····················6-8
Post Calibration Actions ···················6-10
6-6 SOURCE LOCK THRESHOLD CALIBRATION ········6-11
Chapter 7 System Description
7-1 INTRODUCTION ·························7-3
7-2 SYSTEM OVERVIEW ·······················7-3
371XXC MM v

7-3 ANALOG SUBSYSTEM ASSEMBLIES ·············7-7
Signal Source Module ·····················7-7
Test Set Module·························7-8
Receiver Module ························7-9
A8, Source Lock/ Signal Separation and Control PCB · · · 7-10
IF Section ···························7-10
A7PCB,LO3·························7-10
A5 A/D Converter PCB ····················7-11
7-4 DIGITAL SUBSYSTEM ASSEMBLIES·············7-12
A9 Main Processor PCB Assembly ··············7-12
A7 PCB, 10 MHz Time Base················7-13
A13 I/O Interface #1 PCB Assembly ·············7-15
A14 I/O Interface #2 PCB Assembly ·············7-15
A15 Graphics Processor PCB Assembly ···········7-16
A16 Hard Disk PCB Assembly ················7-16
Floppy Disk Drive Assembly ·················7-16
A24 VME Bus Terminator PCB ···············7-16
7-5 MAIN CHASSIS ASSEMBLIES·················7-16
A17 System Motherboard Assembly ·············7-16
Front Panel Assembly ····················7-16
Rear Panel Assembly ·····················7-17
A18 Rear Panel Interface PCB ················7-17
Power Supply Module·····················7-18
Internal LCD ·························7-18
Chapter 8 Remove and Replace Procedures
8-1 INTRODUCTION ·························8-3
8-2 EQUIPMENT REQUIRED ····················8-3
8-3 REMOVE / REPLACE 371XXC COVERS ············8-4
8-4 REMOVE / REPLACE THE A1–A9 AND A13–A16 PCBS····8-6
A1 – A9 PCBs··························8-6
A13 – A16 PCBs ························8-6
8-5 REMOVE / REPLACE A9 PCB BBRAM CHIP ·········8-8
8-6 REMOVE / REPLACE A9 PCB SRAM BATTERY ·······8-10
8-7 REMOVE / REPLACE A24 VME BUS TERMINATOR PCB· · 8-12
8-8 REMOVE / REPLACE FRONT PANEL ASSEMBLY ·····8-13
8-9 LIQUID CRYSTAL DISPLAY (LCD) ··············8-15
8-10 REMOVE / REPLACE FLOPPY DISK DRIVE ·········8-16
8-11 REMOVE / REPLACE REAR PANEL ASSEMBLY·······8-18
8-12 REMOVE / REPLACE FAN ASSEMBLY ············8-19
vi 371XXC MM

8-13 REMOVE / REPLACE POWER SUPPLY MODULE ······8-20
8-14 REMOVE / REPLACE A18 REAR PANEL PCB ········8-21
8-15 REMOVE / REPLACE TEST SET MODULE ASSEMBLIES · 8-22
Buffer Amplifier/ Sampler(A31) ···············8-25
Switched Doubler Module Assembly ·············8-26
8-16 REMOVE / REPLACE SIGNAL SOURCE MODULE ASSEMBLIES
8-27
Removal of Signal Source Module ··············8-27
A21A2 Source Control PCB··················8-29
A21A1 Source YIG Bias Control PCB ············8-29
Switched Filter Assembly···················8-30
Down Converter Assembly ··················8-31
YIG Oscillator Assembly ···················8-31
Appendix A Diagnostics Menus
A-1 INTRODUCTION ·························A-3
A-2 DIAGNOSTICS MENUS ·····················A-3
Start Self Test ·························A-3
Read Service Log························A-3
Installed Options························A-4
Peripheral Tests ························A-4
Troubleshooting ························A-4
H/W Calibrations························A-4
Appendix B Error Messages
B-1 INTRODUCTION ·························B-3
B-2 OPERATIONAL ERROR MESSAGES ··············B-3
B-3 DISK RELATED ERROR MESSAGES··············B-3
B-4 GPIB RELATED ERROR MESSAGES··············B-3
B-5 SERVICE LOG ERROR MESSAGES ··············B-3
0000 - 0099 ···························B-3
0100 - 3999 ···························B-3
4000 - 4999 ···························B-4
5000 - 5999 ···························B-4
6000 - 6999 ···························B-4
7000 - 7999 ···························B-4
8000 - 8999 ···························B-4
371XXC MM vii

Appendix C Connector Maintenance Check Procedures
C-1 INTRODUCTION ·························C-3
C-2 PRECAUTIONS ·························C-3
Pin Depth Problems ······················C-3
Pin-Depth Tolerance ······················C-4
Avoid Over Torquing Connectors ···············C-4
Teflon Tuning Washers ····················C-4
Avoid Mechanical Shock ···················C-4
Keep Connectors Clean ····················C-4
Visual Inspection························C-5
C-3 REPAIR/ MAINTENANCE ···················C-5
Appendix D Performance Specifications
Appendix E Millimeter Wave Service Instructions
E-1 INTRODUCTION ·························E-3
E-2 DESCRIPTION ··························E-3
E-3 REPLACEABLE PARTS ·····················E-4
E-4 PERFORMANCE VERIFICATION–GENERAL ·········E-4
Required Equipment······················E-4
Initial System Setup ······················E-4
E-5 PERFORMANCE VERIFICATION–
IF POWER LEVEL TEST·····················E-6
Test Setup ···························E-6
Test Procedure ·························E-7
E-6 PERFORMANCE VERIFICATION–
HIGH LEVEL NOISE TEST, TRANSMISSION ·········E-8
Test Setup ···························E-8
Test Procedure ························E-10
E-7 PERFORMANCE VERIFICATION–
HIGH LEVEL NOISE TEST, REFLECTION··········E-10
Test Setup ···························E-11
Test Procedure ························E-12
E-8 PERFORMANCE VERIFICATION–
SYSTEM DYNAMIC RANGE TEST ··············E-12
Calibration ··························E-12
Test Procedure ························E-14
viii 371XXC MM

E-9 PERFORMANCE VERIFICATION–
SOURCE MATCH/DIRECTIVITY TEST ············E-15
Test Setup···························E-15
Test Procedure ························E-16
E-10 TROUBLESHOOTING ·····················E-20
Define the Fault Accurately ·················E-20
Isolate the Fault ·······················E-20
Determine the Fault Location ················E-20
If the Fault is in the Signal Sources ·············E-21
If the Fault is in the Test Set·················E-21
RF Components Check ····················E-21
PCB Assembly Voltage Check ················E-22
If the Fault is in the Millimeter Wave Module: ·······E-23
If the Fault is in the VNA ··················E-23
E-11 SYSTEM DESCRIPTION ····················E-24
System Overview ·······················E-24
Signal Sources ························E-25
TestSet····························E-25
Millimeter Wave Modules ··················E-27
Vector Network Analyzer···················E-28
System Operation·······················E-28
E-12 REMOVE AND REPLACE PROCEDURES
(3735B TEST SET)························E-30
Remove Covers ························E-30
Remove Power Supply ····················E-30
Remove Power Distribution PCB ··············E-33
Remove Power Divide/Isolator Assembly ··········E-33
Remove Transfer Switch Assembly ·············E-33
Remove Transfer Switch PCB Assembly ··········E-33
Remove Fan Assembly ····················E-34
Remove Line Voltage Module ················E-34
Appendix F SM5293 and SM5235 Service Information
F-1 INTRODUCTION ·························F-3
F-2 REPLACEABLE EXTERNAL CABLES ·············F-3
F-3 37100C SETUP WITH SM INSTRUMENTS···········F-4
F-4 OPERATIONAL TESTING ····················F-4
Recalibration of the SM5392 and SM5235 ··········F-4
Recalibration Procedure ····················F-5
F-5 TROUBLESHOOTING ······················F-6
371XXC MM ix/x

Table of Contents
1-1 SCOPE OF MANUAL ·······················1-3
1-2 INTRODUCTION ·························1-3
1-3 ONLINE MANUALS ·······················1-3
1-4 IDENTIFICATION NUMBER ··················1-3
1-5 SYSTEM DESCRIPTION ·····················1-4
1-6 RELATED MANUALS·······················1-4
1-7 OPTIONS ·····························1-4
1-8 SERVICE STRATEGY·······················1-4
Functional Assembly Level Troubleshooting ·········1-5
Internal Hardware Adjustments and Calibrations ······1-5
Internal Service Log ······················1-5
System Test/ Certification ···················1-5
Preventive Service ·······················1-6
Servicing Specially Modified Instruments ··········1-6
1-9 SERVICE SUPPORT INFORMATION ··············1-6
Technical Support ·······················1-6
Service Software ························1-7
Test Fixtures/ Aids ·······················1-7
Failed Assembly Exchange Program ·············1-7
1-10 RECOMMENDED TEST EQUIPMENT ·············1-8
1-11 STATIC SENSITIVE COMPONENT
HANDLING PROCEDURES ···················1-9
1-12 SERVICE CENTERS ·······················1-9
1-13 PERFORMANCE SPECIFICATIONS ··············1-9
Chapter 1
General Information

Calibration
Menu
Hard Copy
Markers/Limits
System Stat e
Local Lockou t
SR Q
Listen
Talk
Remote
GPIB
Powe r
b
Defaul t
Progra m Utilit y
Menu Begi n
Ca l Appl y
Ca l
Save /
Recall
Menu
Star t
Prin t
Stop
Prin t
Menu
Limits
Marker
Menu
Readou t
Marker
Graph
Type
Se t
Scal e
Auto
Scal e
S
Params
Re f
Plan e Trac e
Memory
Chann el
Menu Ch 1 Ch 2
Ch 3 Ch 4
Option
Menu
Vide o
IF BW
Avg/
Smoot h
Menu
Trac e
Smoot h
Average
Setu p
Menu
Data
Points
Hold Domain Appl
Ente r
789
456
123
0.-
MH z
ns
X1
cm
GH z10 3
us m
kH z
ps
10
-3
mm
Clear
Ret Loc
Measurement
Enhancement
Chann els
Data Entr y
Displa y
RF Ou t
37147A
Network A nalyzer
22.5MHz - 20GHz
Keyboard
1a1Source Lock
Input Source Lock Output a2Source Lock Input b2
RF In Internal Source
Output
Figure 1-1. Series 37100C Vector Network Analyzer System

1-1 SCOPE OF MANUAL This manual provides general service and preventive maintenance in-
formation for the ANRITSU 371XXC family of Vector Network Ana-
lyzer (VNA) systems. It contains procedures for:
qTesting the instrument for proper operation.
qVerifying measurement accuracy and traceability to National In-
stitute of Standards and Technology (NIST).
qTroubleshooting a failed instrument to the exchange subassem-
bly level or the subsystem requiring adjustment.
qAdjusting instrument internal sub-systems.
qLocating and replacing failed parts.
qInformation on calibration and repair of SM5235 and SM5392
Test Sets (Appendix F).
Throughout this manual, the terms “371XXC” and “371XXC VNA”
will be used interchangeably to refer to all Series 37100C Network
Analyzer system models, unless otherwise noted.
1-2 INTRODUCTION This chapter of the manual provides a general description of 371XXC
VNAsystems, system serial numbers, frequency ranges, and related
manuals. Also included is information about the level of maintenance
covered in this manual, service strategy, available service facilities, and
static-sensitive component handling precautions. Alist of recommended
test equipment is also provided.
1-3 ONLINE MANUALS This manual is available on CD ROM as an Adobe Acrobat™ (*.pdf) file.
The file can be viewed using Acrobat Reader™, a free program that is
also available on the CD ROM. This file is “linked” such that the viewer
can choose a topic to view from the displayed “bookmark” list and “jump”
to the manual page on which the topic resides. The text can also be
word-searched. Acopy of this CD ROM, part number 10920-00036, is pro-
vided free of charge with this manual.
1-4 IDENTIFICATION
NUMBER
All ANRITSU instruments are assigned a six-digit ID number, such as
“401001.” This number appears on a decal affixed to the rear panel.
Please use this identification number during any correspondence with
ANRITSU Customer Service about this instrument.
371XXC MM 1-3
Chapter 1
General Information

1-5 SYSTEM DESCRIPTION The 371XXC Analyzers are microprocessor controlled Vector Network An-
alyzers. Each is a single-instrument system that contains a built-in signal
source, a test set, and an analyzer subsystem. Atypical model (37169C) is
shown in Figure 1-1. These analyzers are produced in two models that
cover a range of from 22.5 MHz to 40 GHz. The table at left lists the fre-
quencies for each model.
1-6 RELATED MANUALS The 37XXXC Vector Network Analyzer Operation Manual (10410-00226)
describes the front panel operation for all 37XXXC models. It also con-
tains general information, specifications, and Performance Verification
procedures for all models.
The 37XXXC Series Vector Network Analyzer Programming Manual
(10410-00227) describes all 37XXXC GPIB commands and provides
programming information for operation of the 37XXXC remotely via
the IEEE-488 General Purpose Interface Bus. Included at the rear of
this manual is the 37XXXC Series Vector Network Analyzer GPIB
Quick Reference Guide (10410-00229).
1-7 OPTIONS The 371XXC VNAoptions and their respective upgrade kit part numbers
that can be installed at ANRITSU Service Centers are:
1-8 SERVICE STRATEGY This paragraph provides an overview of the 371XXC VNAservice strat-
egy and available service facilities. It also provides references to the
information in various locations in this manual needed to accomplish the
service functions required for the 371XXC VNA.
Appendices - Refer to the Appendices at the rear of this manual for de-
tailed descriptions of the following:
qDiagnostic Menus
qGPIB Commands
qError Messages
1-4 371XXC MM
Option Description Upgrade Kit
1 Rack Mount w/slides ND39486
1A Rack Mount ND40916
2A Time Domain (Microwave Units) ND39477
10A High Stability Ovenized Time
Base, 1 Hz Frequency Resolution ND45045
GENERAL SERVICE
INFORMATION STRATEGY
Model Freq Range
37147C 22.5 MHz to 20.0 GHz
37169C 22.5 MHz to 40.0 GHz
371XXC Model Frequencies

Functional Assembly
Level Troubleshooting The 371XXC modular design, extensive built-in diagnostics, and auto-
mated service tools are designed to support fast exchange of functional
assembly level repairs.
Failed assemblies are not field repairable. Once an assembly is found
to be faulty, it should be returned to an authorized ANRITSU Service
Center for exchange. Refer to the description of the Exchange Assem-
bly Program in Chapter 2, Replaceable Parts.
The procedures for troubleshooting a failed 371XXC VNA are de-
scribed in this manual in Chapter 5, Troubleshooting.
Internal Hardware
Adjustments and
Calibrations
There are five automated internal hardware field calibrations. Two of
them are used to characterize the 371XXC frequency and power genera-
tion sub-systems. These calibrations insure fast, consistent phase lock of
system frequencies and proper compensation, leveling, and flatness of
system power at the front panel test ports.
To conduct these calibrations, you need only connect the appropriate
test equipment (counter or power meter) to the 371XXC and initiate
the calibration. The 371XXC will control itself and the externally con-
nected test equipment to perform measurements and store calibration
constants in its internal battery backed RAM (BBRAM).
The procedures for adjusting the 371XXC VNA are described in this
manual in Chapter 6, Adjustments.
Internal Service Log The 371XXC continuously monitors itself for proper operation. Should a
failure occur, it notifies the user via a failure message on the display
screen. (In remote-only operation, it also sets the GPIB Status Byte, if
enabled.) It also writes the error message along with some data pertinent
to the failure to an internal service log stored in battery-backed memory.
The service log can be checked at any time to view (without erasing)
all error messages. It is capable of storing more than 30 pages of ser-
vice messages and data. The 371XXC will automatically remove the
oldest errors first to make room for new errors, if necessary. To check
the contents of the service log, use the procedure described in Chapter
3, Operational Tests.
NOTE
A printed or disk file copy of the Service Log (with the fail-
ure in question) must be made available to ANRITSU
when exchanging a failed assembly, or when requesting
service support. Refer to Chapter 2, Replaceable Parts, for
further information.
System Test/
Certification Quick operational checkout of the system may be accomplished by the
system user or for incoming inspection purposes using the “Operational
Checkout” chapter in the 371XXC Operations Manual. Those procedures
371XXC MM 1-5
SERVICE GENERAL
STRATEGY INFORMATION

are useful in quickly verifying that the instrument’s primary measure-
ment functions are operational and stable.
Full operational testing of the system is detailed in Chapter 3, Opera-
tional Tests. These tests should be performed annually, or more often
depending on system use.
Verification of the system’s measurement accuracy and other key per-
formance parameters may be done using the procedures in Chapter 4,
Performance Verification. This should be performed annually, or more
often depending on system use.
Preventive Service The 371XXC A9 Processor PCB contains a battery-backed memory/real
time clock chip (BBRAM) and a static memory (SRAM) backup battery.
These have a finite life span and should be replaced periodically per the
procedures in Chapter 8, Removal and Replacement Procedures.
The BBRAM chip has a rated life span of four years. The SRAM
backup battery has a worst case elapsed time for SRAM battery pro-
tection of 200 days. The SRAM battery life span will vary according to
how the system is used; that is, how often the system is powered off for
extended periods of time.
Servicing Specially
Modified Instruments Instruments with customer requested special modifications performed by
ANRITSU will have an identifying Specials Modification number printed
on the rear panel. This number will be preceded with the letters SM, i. e.,
SM1234 is special modification number 1234.
Special instruments may have service requirements different from
those specified in this manual. SM5235 and SM5392 are instruments
designed for use with the 37100C VNA. Refer to Appendix F for ser-
vice instructions. Contact your local Service Center if you need more
information when servicing such instruments.
1-9 SERVICE SUPPORT
INFORMATION
The following paragraphs briefly describe the various service support ser-
vices and aids available to you to help you maintain your 371XXC.
Technical Support Technical service support is available by contacting any ANRITSU
Worldwide Service Center (see Chapter 2).
If servicing or repairing your own system and you need technical sup-
port, you will need to provide the items listed below to the ANRITSU
Customer Support Engineer:
qMeasurement data in question
q“Operational Tests” results
qSystem state (from UTILITY menu)
qService Log (from DIAGNOSTICS menu)
1-6 371XXC MM
GENERAL SERVICE SUPPORT
INFORMATION INFORMATION

Service Software The service software listed below is contained on the diskette located at
the rear of this manual:
ANRITSU 37XXX Test Software (2300-178)
This software contains a series of automated tests designed to insure
the 371XXC signal paths are functioning properly and capable of sup-
porting stable calibrations and measurements. See Operational Tests
Chapter for details.
Test Fixtures/ Aids The test fixtures and test aids listed below are available through your lo-
cal ANRITSU Sales or Service Center:
Rear Panel Printer Port Test Fixture (B39553)
This test fixture is used to check out digital printer interface circuits
on the rear panel assembly.
GPIB Cable (2100-2)
This cable is used to check out digital GPIB interface circuits on the
rear panel assembly.
Front Panel Source Lock Test Fixture (ND45331)
This test fixture is used to evaluate system performance.
Front Panel Test Signal Lock Test Fixture (ND45332)
This test fixture is used to evaluate system performance.
Failed Assembly
Exchange Program The exchange program allows a customer to quickly exchange a failed
subassembly for a factory refurbished, fully system-tested end unit that is
under warranty. This results in significant time and price savings as com-
pared with ordering a new assembly.
Refer to Chapter 2, Replaceable Parts, for a complete list of exchange-
able assemblies for all Series 37100C models.
NOTE
When sending a failed assembly to the factory for ex-
change, a copy of the Service Log must always accom-
pany the failed assembly. Refer to Chapter 2, Replaceable
Parts, for further information.
371XXC MM 1-7
SERVICE SUPPORT GENERAL
INFORMATION INFORMATION

1-10 RECOMMENDED TEST
EQUIPMENT
Table 1-1 lists the recommended test equipment to be used for all mainte-
nance activities for all Series 37100C models. Note the “Use” codes
listed in the right hand column of the table. These codes list the appli-
cable maintenance activities for the equipment listed.
1-8 371XXC MM
INSTRUMENT CRITICAL
SPECIFICATION
RECOMMENDED
MANUFACTURER/MODEL USE**
Computer/Controller Equipped with National Instruments
GPIB Interface Adapter, w/Driver Soft-
ware and Windows 95/98
Any O, P
Test Software ANRITSU 2300-178 O
Floppy Disk Formatted, IBM PC format DS/HD 1.44 Mbyte A
GPIB Cable ANRITSU 2100-2, or equivalent O, P, A
RF/Microwave Cable DC – 40 GHz, K type connectors (male
or female), Length, 3 ft.
Any P, A
BNC Cable Length, 4 ft., 2 each Any O
Printer Port Test Fixture ANRITSU B39553 O
Front Panel Source Lock Test Fixture ANRITSU ND45331 O, P
Front Panel Test Signal Test Fixture ANRITSU ND45332 O, P
Fixed Attenuator Contains test data ANRITSU 41KC-10, w/Opt C P
Fixed Attenuator ANRITSU 41KC-3 P
Thru Line ANRITSU 3670K50-2, 3671K50-2 O
Calibration Kit ANRITSU 3652 O, P
Frequency Counter
Frequency: 0.1 to 26.5 GHz
Input Impedance :50W
EIP Microwave, Inc., with GPIB and
Band 3 Input
P, A
Digital Multimeter
Resolution: 412digits
DC Accuracy: 0.1 %
AC Accuracy: 0.1 %
Any T
Oscilloscope
Bandwidth: DC to 100 MHz
Sensitivity: 2mV
Horiz. Sensitivity: 50 ns/division
Any T
Power Meter and
Power Sensor
Anritsu Model ML243xA Power Me-
ter, with MA2474A
P, A
Gauging Set GPC-7 Gauging Set
K Connector Gauging Set
ANRITSU 01-161
ANRITSU 01-162
O, T
** USE CODES:
A Adjustment / Internal Hardware Calibration
O Operational Testing
P Performance Verification
T Troubleshooting
Table 1-1. Recommended Test Equipment (1 of 1)
RECOMMENDED TEST GENERAL
EQUIPMENT INFORMATION

1-11 STATIC SENSITIVE
COMPONENT
HANDLING
PROCEDURES
The 371XXC contains components that can be damaged by static electric-
ity. Figure 1-2 (next page) illustrates the precautions that should be fol-
lowed when handling static-sensitive subassemblies and components. If
followed, these precautions will minimize the possibilities of static-shock
damage to these items.
1-12 SERVICE CENTERS ANRITSU Company offers a full range of repair and calibration services
at fully staffed and equipped service centers throughout the world. Table
2-1, located on page 2-4, lists all ANRITSU service centers.
1-13 PERFORMANCE
SPECIFICATIONS
The performance specifications for all Series 371XXC models are con-
tained in the Technical Data Sheet that is located in Appendix D, Per-
formance Specifications.
371XXC MM 1-9
GENERAL SERVICE
INFORMATION CENTERS