Service Guide
N9912A
Agilent Technologies
RF Analyzer
(2 MHz – 4 GHz)
(2 MHz – 6 GHz)
Part Number N9912-90003
Printed in USA
March 23, 2011
Supersedes Print Date: August 2009
© Agilent Technologies, Inc. 2008, 2009, 2011
Warranty Statement
THE MATERIAL CONTAINED IN THIS DOCUMENT IS PRO VIDED “AS I S,” AND IS SUBJECT
TO BEING CHANGED, WITHOUT NOTICE, IN FUTURE EDITIONS. FURTHER, TO THE
MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, AGILENT DISCLAIMS ALL
WARRANTIES, EITHER EXPRESS OR IMPLIED WITH REGARD TO THIS MANUAL AND
ANY INFORMATION CONTAINED HEREIN, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE. AGILENT SHALL NOT BE LIABLE FOR ERRORS OR FOR INCIDENTAL
OR CONSEQUENTIAL DAMAGES IN CONNECTION WITH THE FURNISHING, USE, OR
PERFORMANCE OF THIS DOCUMENT OR ANY INFORMA TI ON CONTAINED HEREIN.
SHOULD AGILENT AND THE USER HAVE A SEPARATE WRITTEN AGREEMENT W ITH
WARRANTY TERMS COVERING THE MATERIAL IN THIS DOCUMENT THAT CONFLICT
WITH THESE TERMS, THE WARRANTY TERMS IN THE SEPARATE AGREEMENT WILL
CONTROL.
DFARS/Restricted Rights Notice
If software is for use in the performance of a U.S. Government prime contract or
subcontract, Software is delivered and licensed as “Commercial computer software” as
defined in DFAR 252.227-7014 (June 1995), or as a “commercial item” as defined in FAR
2.101(a) or as “Restricted computer software” as defined in FAR 52.227-19 (June 1987) or
any equivalent agency regulation or contract clause. Use, duplication or disclosure of
Software is subject to Agilent Technologies’ standard commercial license terms, and
non-DOD Departments and Agencies of the U.S. Government will receive no greater than
Restricted Rights as defined in FAR 52.227-19(c)(1-2) (June 1987). U.S. Government users
will receive no greater than Limited Rights as defined in FAR 52.227-14 (June 1987) or
DFAR 252.227-7015 (b)(2) (November 1995), as applicable in any technical data.
Certification
Agilent Technologies, Inc. certifies that this product met its published specifications at the
time of shipment from the factory. Agilent Technologies, Inc. further certifies that its
calibration measurements are traceable to the United States National Institute of
Standards and Technology, to the extent allowed by the Institute's calibration facility, and
to the calibration facilities of other International Standards Organization members.
ii Service Guide N9912-90003
Assistance
Product maintenance agreements and other customer assistance agreements are available
for Agilent Technologies, Inc. products. For information about these agreements and for
other assistance, contact Agilent. Refer to “Contacting Agilent” on page 2-5.
Safety and Regulatory Information
The safety and regulatory information pertaining to this product is located in Chapter 1,
“Safety and Regulatory Information.”
Safety Notes
The following safety notes are used throughout this manual. Familiarize yourself with
each of the notes and its meaning before operating this instrument. All pertinent safety
notes for using this product are located in Chapter 1, “Safety and Regulatory Information.”
WARNING Warning denotes a hazard. It calls attention to a procedure which, if
not correctly performed or adhered to, could result in injury or loss
of life. Do not proceed beyond a warning note until the indicated
conditions are fully understood and met.
CAUTION Caution denotes a hazard. It calls attention to a procedure that, if not
correctly performed or adhered to, could result in damage to or destruction of
the instrument. Do not proceed beyond a caution sign until the indicated
conditions are fully understood and met.
Service Guide N9912-90003 iii
Documentation Map
This Service Guide is available only on the Web via an Internet
connection. It contains information for testing, adjusting,
troubleshooting, and repairing your N9912A analyzer.
The User’s Guide, included with the product, helps you to quickly
familiarize yourself with the analyzer. Procedures are provided for
preparing, configuring, and making measurements with the analyzer.
The Quick Reference Guide, included with the product, is an
abbreviated form of the User’s Guide containing some of the most
commonly referred to information. The pages of the Quick Reference
Guide are laminated with clear plastic to resist damage when used
outdoors.
Printing Copies of Documentation from the Web
To print copies of documentation from the Web, download the PDF file from the Agilent
web site:
•Go to www.agilent.com.
• Enter the document’s part number (located on the title page) in the Search box.
• Click Search.
iv Service Guide N9912-90003
Contents
1 Safety and Regulatory Information
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Chapter One at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-2
Safety Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Safety Earth Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-3
Before Applying Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Servicing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-4
Electrostatic Discharge Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-5
Regulatory Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Instrument Markings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-6
Battery Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1-7
2 General Product Information
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Chapter Two at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-2
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Physical Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Electrical Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Analyzer Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 110, Transmission Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 111, QuickCal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 230, 4 GHz Spectrum Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 231, 6 GHz Spectrum Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 235, Preamplifier for Spectrum Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-3
Option 302, External USB Power Sensor Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Option 303, Network Analyzer Capability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Agilent Support, Services, and Assistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Service and Support Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Calibration Options. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-4
Contacting Agilent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
Shipping Your Analyzer to Agilent for Service or Repair . . . . . . . . . . . . . . . . . . . . . . . . . . .2-5
3Tests and Adjustments
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Chapter Three at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-2
Before You Begin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Allow the Analyzer to Warm Up. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-3
Review the Principles of Connector Care. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
Service Test Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-5
Before Returning an Instrument to a Customer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Operational Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-6
Performance Tests (Agilent N7841A Software Package) . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
General Tests. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Spectrum Analyzer Specific Tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-7
Adjustments (Agilent N7841A Software Package). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
General Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-8
Service Guide N9912-90003 Contents-1
Contents
Spectrum Analyzer Specific Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-8
4 Troubleshooting
Information in This Chapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-2
Chapter Four at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-2
Protect Against Electrostatic Discharge (ESD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Assembly Replacement Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-3
Getting Started with Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Check the Basics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4
Troubleshooting Organization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-5
Power Up Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4-6
Front Panel Group Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Measurement Group Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-8
5 Theory of Operation
Information in This Chapter. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-2
Chapter Five at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-2
Analyzer System Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Functional Groups of the Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-3
Front Panel Group. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
A3 Front Panel Interface Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-5
A2 LCD Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-6
Measurement Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
A4 RF Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-7
A5 System Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-12
A6 SOM Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Main Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-16
Grounding and Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-17
Grounding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Voltages and Power Supplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-17
Power Control and Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-18
Battery Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-19
Operation in Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-21
CAT and NA Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-22
SA Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-24
Power Meter Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
Temperature Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-25
User Calibration in CAT and NA Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-26
One Port Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-26
Two Port Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-27
QuickCal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-27
Firmware Related Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-28
User Accessible Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-28
Operational Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Erase User Data Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-28
Error Log. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Firmware Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-29
Contents-2 Service Guide N9912-90003
Contents
LAN Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5-30
6Replaceable Parts
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-2
Chapter Six at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-2
Ordering Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-3
Assembly Replacement Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-4
Replaceable Parts Listings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Entire Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-5
Front Panel Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-6
Measurement Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-8
Case Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-10
Miscellaneous Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6-12
7 Repair and Replacement Procedures
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
Chapter Seven at-a-Glance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-2
Personal Safety Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
Safety Earth Ground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
Electrostatic Discharge (ESD) Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-3
Assembly Replacement Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
Removal and Replacement Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-4
Removing and Replacing the Main Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-5
Removing and Replacing the Case Group Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-6
Removing and Replacing the Front Panel Group Assemblies . . . . . . . . . . . . . . . . . . . . . . . .7-18
Removing and Replacing the Measurement Group Assemblies . . . . . . . . . . . . . . . . . . . . . .7-25
Post-Repair Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-39
Manual Checks and Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-40
8 General Purpose Maintenance and Service Procedures
Information in This Chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
Chapter Eight at-a-Glance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-2
Service Related User Operations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
To View Currently Installed Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
To View the Current Firmware Revision, Etc. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
To View the Error Log . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
To View Temperature Readings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-3
Erase User Data Utility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-4
Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-5
To View Currently Installed Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-5
Re-Installing Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-5
Firmware Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-6
To Check the Current Firmware Revision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-6
Miscellaneous Service and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-7
Cleaning the Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-7
Battery Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8-7
Service Guide N9912-90003 Contents-3
Contents
Contents-4 Service Guide N9912-90003
1 Safety and Regulatory Information
Service Guide N9912-90003 1-1
Safety and Regulatory Information RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
This chapter provides safety information that will help protect you and your network
analyzer. It also contains information that is required by various government regulatory
agencies.
Chapter One at-a-Glance
Section Title Summary of Content Start Page
Safety Symbols
General Safety Considerations
Electrostatic Discharge
Protection
Regulatory Information
Descriptions of CAUTION and WARNING
symbols used throughout this manual.
A list of safety points to consider when
servicing your network analyzer.
A discussion of electrostatic discharge (ESD)
and related recommendations and
requirements for ESD protection.
Definitions of instrument markings.
Instructions for disposing of the analyzer’s
lithium battery.
Page 1-3
Page 1-3
Page 1-5
Page 1-6
1-2 Service Guide N9912-90003
RF Analyzer Safety and Regulatory Information
N9912A Safety Symbols
Safety Symbols
The following safety symbols are used throughout this manual. Familiarize yourself with
each of the symbols and its meaning before operating this instrument.
CAUTION Caution denotes a hazard. It calls attention to a procedure that, if not
correctly performed or adhered to, could result in damage to or destruction of
the instrument. Do not proceed beyond a caution note until the indicated
conditions are fully understood and met.
WARNING Warning denotes a hazard. It calls attention to a procedure which, if
not correctly performed or adhered to, could result in injury or loss
of life. Do not proceed beyond a warning note until the indicated
conditions are fully understood and met.
General Safety Considerations
Safety Earth Ground
WARNING This is a Safety Class I product (provided with a protective earthing
ground incorporated in the power cord). The mains plug shall only
be inserted in a socket outlet provided with a protective earth
contact. Any interruption of the protective conductor, inside or
outside of the instrument, will make the instrument dangerous.
Intentional interruption is prohibited.
CAUTION Always use the three-prong AC power cord supplied with this product.
Failure to ensure adequate grounding by not using this cord may cause
product damage.
Service Guide N9912-90003 1-3
Safety and Regulatory Information RF Analyzer
General Safety Considerations N9912A
Before Applying Power
WARNING If this product is not used as specified, the protection provided by
the equipment could be impaired. This product must be used in a
normal condition (in which all means for protection are intact) only.
CAUTION This product is designed for use in Installation Category II and Pollution
Degree 2 per IEC 61010-1:2001 and 664 respectively.
CAUTION The measuring terminals on this instrument are designed to be used with
external signals described in Measurement Category I, but NOT with
external signals described in Categories II, III, and IV. The input of this
instrument cannot be connected to the mains.
Servicing
WARNING These servicing instructions are for use by qualified personnel only.
To avoid electrical shock, do not perform any servicing unless you
are qualified to do so.
WARNING Danger of explosion if battery is incorrectly replaced. Replace only
with the same or equivalent type recommended. Discard used
batteries according to local ordinances and/or manufacturer’s
instructions.
WARNING No operator serviceable parts inside. Refer servicing to qualified
personnel. To prevent electrical shock, do not remove covers.
WARNING For continued protection against fire hazard, replace line fuse only
with same type and rating. The use of other fuses or material is
prohibited.
WARNING The detachable power cord is the instrument disconnecting device.
It disconnects the mains circuits from the mains supply before other
parts of the instrument. The front panel switch is only a standby
switch and is not a LINE switch (disconnecting device).
1-4 Service Guide N9912-90003
RF Analyzer Safety and Regulatory Information
N9912A Electrostatic Discharge Protection
Electrostatic Discharge Protection
Protection against electrostatic discharge (ESD) is essential while removing assemblies
from or connecting cables to the network analyzer. Static electricity can build up on your
body and can easily damage sensitive internal circuit elements when discharged. Static
discharges too small to be felt can cause permanent damage. To prevent damage to the
instrument:
• always have a grounded, conductive table mat in front of your test equipment.
• always wear a grounded wrist strap, connected to a grounded conductive table mat,
having a 1 MΩ resistor in series with it, when handling components and assemblies or
when making connections.
• always wear a heel strap when working in an area with a conductive floor. If you are
uncertain about the conductivity of your floor, wear a heel strap.
• always ground yourself before you clean, inspect, or make a connection to a
static-sensitive device or test port. You can, for example, grasp the grounded outer shell
of the test port or cable connector briefly.
• always ground the center conductor of a test cable before making a connection to the
analyzer test port or other static-sensitive device. This can be done as follows:
1. Connect a short (from your calibration kit) to one end of the cable to short the center
conductor to the outer conductor.
2. While wearing a grounded wrist strap, grasp the outer shell of the cable connector.
3. Connect the other end of the cable to the test port and remove the short from the
cable.
Figure 1-1 shows a typical ESD protection setup using a grounded mat and wrist strap.
Refer to “ESD Supplies” on page 6-12 for part numbers.
Figure 1-1 ESD Protection Setup
Service Guide N9912-90003 1-5
Safety and Regulatory Information RF Analyzer
Regulatory Information N9912A
Regulatory Information
This section contains information that is required by various government regulatory
agencies.
Instrument Markings
The instruction documentation symbol. The product is marked with
this symbol when it is necessary for the user to refer to the
instructions in the documentation.
The CE mark is a registered trademark of the European Community.
(If accompanied by a year, it is when the design was proven.)
The CSA mark is a registered trademark of the Canadian Standards
Association.
ICES/NMB-001
This is a marking to indicate product compliance with the Canadian
Interference-Causing Equipment Standard (ICES-001).
This is a symbol of an Industrial Scientific and Medical Group 1
Class A product.
This is a required mark signifying compliance with an EMC
requirement. The C-Tick mark is a registered trademark of the
Australian Spectrum Management Agency.
This product complies with the WEEE Directive (2002/96/EC) marking
requirements. The affixed label indicates that you must not discard this
electrical/ electronic product in domestic household waste.
Product Category: With reference to the equipment types in the WEEE
Directive Annex I, this product is classed as a “Monitoring and Control
instrumentation” product.
Do not dispose in domestic household waste.
To return unwanted products, contact your local Agilent office, or
see http://www.agilent.com/environment/product/ for more
information.
1-6 Service Guide N9912-90003
RF Analyzer Safety and Regulatory Information
N9912A Regulatory Information
Battery Disposal
If the either the primary power battery, or the RTC (real time clock) battery (on the A3
front panel interface board) needs to be disposed of, dispose of it in accordance with your
country’s requirements. If required, you may return the battery to Agilent Technologies for
disposal. Refer to “Contacting Agilent” on page 2-5 for assistance.
For instructions on removing and replacing the primary power battery, refer to “Removing
and Replacing the Main Battery” on page 7-5.
For instructions on removing and replacing the RTC (real time clock) battery located on
the A3 front panel interface board, refer to “Replacing the A3 Front Panel Interface Board
(FPIB)” on page 7-22.
Service Guide N9912-90003 1-7
Safety and Regulatory Information RF Analyzer
Regulatory Information N9912A
1-8 Service Guide N9912-90003
2 General Product Information
Service Guide N9912-90003 2-1
General Product Information RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
Chapter Two at-a-Glance
Section Title Summary of Content Start Page
Cleaning instructions for the external surfaces of
Maintenance
your analyzer.
Page 2-3
Information about electrical maintenance of your
analyzer.
Analyzer Options
Agilent Support, Services, and
Assistance
A list of the options available for the microwave
network analyzers.
The Internet address (URL) for Agilent assistance.
Service and support options available.
Calibration options available.
Important information about shipping your
analyzer to Agilent for service or repair.
Page 2-3
Page 2-4
2-2 Service Guide N9912-90003
RF Analyzer General Product Information
N9912A Maintenance
Maintenance
WARNING To prevent electrical shock, disconnect the analyzer from the mains
source before cleaning. Use a dry cloth or one slightly dampened
with water to clean the external case parts. Do not attempt to clean
internally.
Physical Maintenance
Clean the analyzer case using a dry or slightly damp cloth only.
Electrical Maintenance
Refer to “Contacting Agilent” on page 2-5 and to Chapter 3, “Tests and Adjustments.”
Analyzer Options
Below is a list of options available for the FieldFox N9912A at the time of initial product
release. Additional options will be added as product features are enhanced. Go to
www.agilent.com/find/fieldfox2 for information on currently available upgrade options.
Option 110, Transmission Measurement
This option allows use of the second port in either the NA (network analyzer) or CAT (cable
and antenna test) modes for transmission measurements.
Option 111, QuickCal
This option provides a calibration that is performed automatically using calibration
standards that are built-in to the N9912A. Calibration standards are automatically
switched in as needed. QuickCal is ideal for making quick DTF and cable loss
measurements without taking the time to perform a full O,S,L Cal.
Option 230, 4 GHz Spectrum Analyzer
This option allow the N9912A to make spectrum analyzer measurements from 100 kHz to
4 GHz. This option can be installed only on a 4 GHz unit.
Option 231, 6 GHz Spectrum Analyzer
This option allow the N9912A to make spectrum analyzer measurements from 100 kHz to
6 GHz. This option can be installed only on a 6 GHz unit.
Option 235, Preamplifier for Spectrum Analyzer
This option adds a preamplifier to the input port for spectrum analyzer measurements.
Service Guide N9912-90003 2-3
General Product Information RF Analyzer
Agilent Support, Services, and Assistance N9912A
Option 302, External USB Power Sensor Support
This option allows the use of an external USB controllable power sensor.
Option 303, Network Analyzer Capability
This option allows the N9912A to make one-port network analyzer measurements. For
two-port network analyzer measurements, add Option 110.
Agilent Support, Services, and Assistance
Information on the following topics is included in this section.
• “Service and Support Options”
• “Calibration Options”
• “Contacting Agilent”
• “Shipping Your Analyzer to Agilent for Service or Repair”
Service and Support Options
The analyzer’s standard warranty is a one-year return to Agilent Technologies service
warranty.
NOTE There are other repair and calibration options available from Agilent
Technologies. Contact Agilent for additional information on available service
agreements for this product. Refer to “Contacting Agilent” on page 2-5.
Calibration Options
Commercial Calibration Certificate with Test Data
A complete set of measurements that test the analyzer to the manufacturer’s published
specifications. It includes a calibration label, a calibration certificate, and the
corresponding calibration data report. This calibration conforms to ISO 9001.
ISO 17025 Standards Compliant Calibration
A complete set of measurements that test the analyzer to the manufacturer’s published
specifications. It includes a calibration label, an ISO 17025 calibration certificate, and the
corresponding calibration data, measurement uncertainties, and guardbands on all
customer specifications. This calibration conforms to ISO 17025 and ISO 9001.
This calibration option is available at the time of purchase or can be obtained later by
sending your analyzer to Agilent for calibration. Refer to “Shipping Your Analyzer to
Agilent for Service or Repair”.
2-4 Service Guide N9912-90003
RF Analyzer General Product Information
N9912A Agilent Support, Services, and Assistance
ANSI Z540 Standards Compliant Calibration
A complete set of measurements that test the analyzer to the manufacturer’s published
specifications. It includes both pre- and post-adjustment data with measurement
uncertainty information compliant to the ANSI/NCSL Z540 standard.
This calibration option is available at the time of purchase or can be obtained later by
sending your analyzer to Agilent for calibration. Refer to “Shipping Your Analyzer to
Agilent for Service or Repair”.
Contacting Agilent
Assistance with test and measurements needs and information on finding a local Agilent
office are available on the Web at:
http://www.agilent.com/find/assist
If you do not have access to the Internet, please contact your Agilent field engineer.
NOTE In any correspondence or telephone conversation, refer to the Agilent product
by its model number and full serial number. With this information, the
Agilent representative can determine whether your product is still within its
warranty period.
Shipping Your Analyzer to Agilent for Service or Repair
IMPORTANT Agilent Technologies reserves the right to reformat or replace the internal
hard disk drive in your analyzer as part of its repair. This will erase all user
information stored on the hard disk. It is imperative, therefore, that you
make a backup copy of your critical test data located on the analyzer’s hard
disk before shipping it to Agilent for repair.
If you wish to send your network analyzer to Agilent Technologies for service or repair:
• Include a complete description of the service requested or of the failure and a
description of any failed test and any error message.
• Ship the analyzer using the original or comparable antistatic packaging materials.
• Contact Agilent for instructions on where to ship your analyzer. Refer to “Contacting
Agilent” on page 2-5.
Service Guide N9912-90003 2-5
General Product Information RF Analyzer
Agilent Support, Services, and Assistance N9912A
2-6 Service Guide N9912-90003
3 Tests and Adjustments
Service Guide N9912-90003 3-1
Tests and Adjustments RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
This chapter contains procedures to help you check, verify, and adjust your N9912A
analyzer.
• The checks verify the operation of the assemblies in your analyzer.
• The adjustments allow you to tune your analyzer for maximum response.
NOTE The Agilent N7841A software package is required to test and adjust your
analyzer. This software package must be purchased separately. It can be
downloaded from the Internet and a license purchased on-line, or it can be
ordered on a CD-ROM. Go to www.agilent.com/find/calibrationsoftware for
further information. The help file for the N7841A software package is also
available at this URL.
Chapter Three at-a-Glance
Section Title Summary of Content Start Page
Items to consider or procedures to perform before
testing is begun:
•
Verify the operating environment.
Before You Begin
Service Test
Equipment
Before Returning an
Instrument to a
Customer
Operational Check
Performance Tests
(Agilent N7841A
Software Package)
a
• Protect Against Electrostatic Discharge (ESD)
• Allow the Analyzer to Warm Up
• Review the Principles of Connector Care
A list of additional equipment recommended for
servicing the N9912A analyzer.
A list of things to do before returning an instrument to
a customer after servicing is completed.
An operation check that should be performed before
returning an instrument to a customer.
A list of performance tests included in the Agilent
N7841A software package.
Page 3-3
Page 3-5
Page 3-6
Page 3-6
Page 3-7
Adjustments (Agilent
N7841A Software
Package)
3-2 Service Guide N9912-90003
a
a. The Agilent N7841A software package must be purchased separately. Go to
www.agilent.com/find/calibrationsoftware for information.
A list of adjustments included in the Agilent N7841A
software package.
Page 3-8
RF Analyzer Tests and Adjustments
N9912A Before You Begin
Before You Begin
Before checking, verifying, or adjusting the analyzer, refer to the following paragraphs to:
• Make sure the operating environment is within 19 to 27 ° C and 5 to 95% humidity.
• Make sure that proper electrostatic discharge (ESD) protection is provided.
• Review the principles of connector care.
Protect Against Electrostatic Discharge (ESD)
This is important. If not properly protected against, electrostatic discharge can seriously
damage your analyzer, resulting in costly repair.
CAUTION To reduce the chance of electrostatic discharge, follow all of the
recommendations outlined in “Electrostatic Discharge Protection” on
page 1-5, for all of the procedures in this chapter.
Allow the Analyzer to Warm Up
Before testing or adjusting the N9912A analyzer, allow it to warm up as described under
“DUT Warmup” in the “Getting Started” section of the N7841A help file.
Service Guide N9912-90003 3-3
Tests and Adjustments RF Analyzer
Before You Begin N9912A
Review the Principles of Connector Care
Proper connector care and connection techniques are critical for accurate and repeatable
measurements. Refer to Table 3-1 for tips on connector care.
Prior to making connections to your analyzer, carefully review the information about
inspecting, cleaning, and gaging connectors. Refer to the calibration kit documentation for
detailed connector care information.
For course numbers about additional connector care instruction, contact Agilent
Technologies. Refer to “Contacting Agilent” on page 2-5.
Table 3-1 Connector Care Quick Reference Guide
Handling and Storage
Do • Keep connectors clean Do Not • Touch mating-plane surfaces
• Extend sleeve or connector nut • Set connectors contact-end down
• Use plastic end-caps during storage • Store connectors or adapters loose
Visual Inspection
Do • Inspect all connectors carefully Do Not • Use a damaged connector - ever
• Look for metal particles, scratches,
and dents
Connector Cleaning
Do • Try compressed air first Do Not • Use any abrasives
• Use isopropyl alcohol
• Clean connector threads
Do • Clean and zero the gage before use Do Not • Use an out-of-specification
• Use the correct gage type
• Use correct end of calibration block
• Gage all connectors before first use
Do • Align connectors carefully Do Not • Apply bending force to connection
• Make preliminary connection contact
lightly
• Turn only the connector nut • Twist or screw any connection
• Use a torque wrench for final
connection
a
Gaging Connectors
Making Connections
• Get liquid into plastic support
beads
connector
• Over tighten preliminary
connection
• Tighten past torque wrench
“break” point
a. Cleaning connectors with alcohol shall only be done with the instrument’s power cord
removed, and in a well-ventilated area. Allow all residual alcohol moisture to evaporate,
and the fumes to dissipate prior to energizing the instrument.
3-4 Service Guide N9912-90003
RF Analyzer Tests and Adjustments
N9912A Service Test Equipment
Service Test Equipment
The test equipment required for the TME based N7841A test and adjustment software is
listed in the N7841A help file.
The following additional test equipment is recommended when servicing the N9912A
analyzer:
• Main Battery—Required if the analyzer is returned for service without a battery.
Refer to Table 6-1 on page 6-12 for part numbers.
• USB flash drive—Used for firmware upgrades, option installation, etc. Also known as
USB memory stick. Must be 128 MB or larger.
• Small, free-standing fan—Used to cool the analyzer if internal temperature is too
high. See “DUT Warmup” in the “Getting Started” section of the N7841A help file for
usage instructions. Generic small office fan of approximately six inches in diameter is
sufficient.
• Type-N male cal kit—Tee cal kit, part number 1250-3607, is recommended. This
matches the default cal kit definition stored in the analyzer. Cal kits 85032E/F or
85054B/D may be substituted.
• Mini SD flash card—Required to re-load firmware onto the A6 SOM board. A “mini”
sized Secure Digital (SD) flash memory card is between “standard” and “micro” sizes.
The memory size must be at least 64 MB and not greater than 2 GB. This card is not
available from Agilent. To identify a supplier, search the Web for “mini sd card”.
• Stereo headphones or ear buds—May be used to troubleshoot sound output if there
is a problem with the internal speaker.
Service Guide N9912-90003 3-5
Tests and Adjustments RF Analyzer
Before Returning an Instrument to a Customer N9912A
Before Returning an Instrument to a Customer
When finished servicing an N9912A analyzer, perform the following before returning the
unit to the customer:
• Set the Display Colors to Indoors and the display Brightness to 80% via
Service (7) > Display.
• Perform an Operational Check as described in the following section.
• Connect and disconnect the external battery charger while the N9912A is operating and
confirm that the power cord icon is displayed appropriately at the top of the display.
• Charge the battery to 80% or higher.
Operational Check
1. Preset the instrument, press Preset (.) > Preset.
2. Leave the RF OUT connector open.
3. Press: Scale/Amptd > Ref Pos > 2 > Enter
4. The trace should be within +/- 5 dB of 0.00 dB.
5. Connect a known good load to the RF OUT connector.
6. The trace should be below 30 dB.
7. Press: Measure > More. If an Insertion Loss softkey is displayed, then do the following:
a. Press: Insertion Loss.
b. Connect a short cable between the RF OUT and RF IN connectors.
c. The trace should be within +/- 15 dB of 0.00 dB.
8. Press: Mode. If an SA softkey is displayed, then do the following:
a. Press: SA
b. Leave the RF IN connector open.
c. Between 30 MHz and 5 GHz, the trace should be below -45 dBm.
d. Between 5 GHz and 6 GHz, the trace should be below -35 dBm.
NOTE If the operational check fails, allow the instrument to warm up for 15 minutes
and try again.
3-6 Service Guide N9912-90003
RF Analyzer Tests and Adjustments
N9912A Performance Tests (Agilent N7841A Software Package)
Performance Tests (Agilent N7841A Software Package)
The performance tests section of the Agilent N7841A software package verifies the
electrical performance of your N9912A analyzer. The software automatically configures
your analyzer to execute the performance tests.
The N7841A software package is not included with the analyzer; it must be ordered
separately. It can be downloaded from the Internet and a license purchased on-line, or it
can be ordered on a CD-ROM. Go to www.agilent.com/find/calibrationsoftware for further
information.
There are:
• Four tests for the general functionality of the analyzer.
• Seven additional tests for the SA (spectrum analyzer) functions.
Total test time will vary from 7 to 36 minutes depending upon options installed.
Details for these tests and recommended troubleshooting information can be found in the
N7841A help file.
General Tests
Total test time for these tests is 8 minutes.
• Frequency Accuracy Test
• Error Terms Test (CAT Functional)—This test includes an adjustment (see
“Adjustments (Agilent N7841A Software Package)” on page 3-8) and should be
performed every 12 months.
• High/Low Output Power Output Test (CAT Functional)
• Crosstalk S21 Test (CAT Functional)
Spectrum Analyzer Specific Tests
Total test time for these tests is 29 minutes.
• Absolute Amplitude Accuracy Test
• IF Frequency Response Test (Functional)
• Frequency Response with Preamp Off Test
• Frequency Response with Preamp On Test
• Displayed Average Noise Level with Preamp On Test
• Noise Sidebands Test
Service Guide N9912-90003 3-7
Tests and Adjustments RF Analyzer
Adjustments (Agilent N7841A Software Package) N9912A
Adjustments (Agilent N7841A Software Package)
The adjustments section of the Agilent N7841A software package may be used to fine-tune
your analyzer.
The N7841A software package is not included with the analyzer; it must be ordered
separately. It can be downloaded from the Internet and a license purchased on-line, or it
can be ordered on a CD-ROM. Go to www.agilent.com/find/calibrationsoftware for further
information.
These adjustments consist of:
• Three general adjustments that are used to adjust the general functions of the analyzer.
• Seven adjustments specifically for the SA (spectrum analyzer) functions.
Total adjustment time will vary from 1 to 80 minutes depending upon options installed.
If multiple adjustments are to be performed, perform them in the order listed by the
N7841A software.
Details for these adjustments, and recommended troubleshooting information, can be
found in the N7841A help file.
General Adjustments
Total time for these adjustments is six minutes.
• “Frequency Accuracy”
• “ADC Overload Adjustment”
• “Error Terms (NA) Adjustment”—This adjustment is part of the Error Terms Test (see
“Performance Tests (Agilent N7841A Software Package)” on page 3-7) and should be
performed every 12 months. It refreshes the definition of the preset calibration.
Spectrum Analyzer Specific Adjustments
Total time for these adjustments is 75 minutes.
• “IF Frequency Response Adjustment”
• “Absolute Amplitude Adjustment”
• “Frequency Response with Preamp On Adjustment”
• “Frequency Response with Preamp Off Adjustment”
• “Attenuator Slope Adjustment”
•“IF Offset Adjustment”
• “Spur Dodging Adjustment”
3-8 Service Guide N9912-90003
4 Troubleshooting
Service Guide N9912-90003 4-1
Troubleshooting RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
The information in this chapter helps you:
• Identify the portion of the analyzer at fault.
• Locate the specific troubleshooting procedure to identify the assembly or peripheral at
fault.
The sections in this chapter are arranged in a logical troubleshooting order. The following
table lists the sections and a brief summary of what to look for in that section.
Chapter Four at-a-Glance
Section Title Summary of Content Start Page
‘Getting Started with
Troubleshooting’
‘Power Up Troubleshooting’
‘Front Panel Group
Troubleshooting’
‘Measurement Group
Troubleshooting’
A starting point to begin troubleshooting. Page 4-4
Power-up problems:
• Power supply problems
• Problems with the front panel assemblies
of the analyzer.
Problems with the measurement group
assemblies of the analyzer.
Page 4-6
Page 4-7
Page 4-8
4-2 Service Guide N9912-90003
RF Analyzer Troubleshooting
N9912A Protect Against Electrostatic Discharge (ESD)
Protect Against Electrostatic Discharge (ESD)
This is important. If not properly protected against, electrostatic discharge can seriously
damage your analyzer, resulting in costly repair.
CAUTION To reduce the chance of electrostatic discharge, follow all of the
recommendations outlined in “Electrostatic Discharge Protection” on
page 1-5, for all of the procedures in this chapter.
Assembly Replacement Sequence
After identifying the problem requiring an assembly to be replaced, follow these steps:
Step 1. Order a replacement assembly. Refer to Chapter 6, “Replaceable Parts.”
Step 2. Replace the faulty assembly and determine what adjustments are necessary.
Refer to Chapter 7, “Repair and Replacement Procedures.”
Step 3. Perform the necessary adjustments. Refer to Chapter 3, “Tests and Adjustments.”
Step 4. Perform the necessary performance tests. Refer to Chapter 3, “Tests and
Adjustments.”
Service Guide N9912-90003 4-3
Troubleshooting RF Analyzer
Getting Started with Troubleshooting N9912A
Getting Started with Troubleshooting
Where you begin troubleshooting depends upon the symptoms of the failure. Start by
checking the basics as outlined in the following section. Also review the flowchart in Figure
4-1 on page 4-5. You should then be able to determine where in the troubleshooting
procedure to begin, to locate the failed assembly.
Check the Basics
A problem can often be solved by repeating the procedure you were following when the
problem occurred. Before calling Agilent Technologies or returning the instrument for
service, please perform the following checks:
1. Does the analyzer have power available? It is recommended that the battery is installed
and the AC power adapter is also connected.
2. Does the analyzer turn On and Off when the On/Off Button is pressed? When the unit is
on, the green LED below the button should light.
3. Does the analyzer power up normally into CAT mode? If not, see “Power Up
Troubleshooting” on page 4-6.
4. If other equipment, cables, and connectors are being used with the analyzer, make sure
they are clean, connected properly and operating correctly.
5. Review the procedure for the measurement being performed when the problem
appeared. Are all the settings correct? If not, correct them.
6. If the analyzer is not functioning as expected, return it to a known state by pressing the
Preset key.
7. If the problem is thought to be due to firmware, check to see if the instrument has the
latest firmware before starting the troubleshooting procedure. Refer to “Firmware
Upgrades” in Chapter 8 for instructions.
4-4 Service Guide N9912-90003
RF Analyzer Troubleshooting
N9912A Getting Started with Troubleshooting
Troubleshooting Organization
Follow the flowgraph in Figure 4-1 to help direct you to the correct section for
troubleshooting the analyzer.
Figure 4-1 Troubleshooting Organization Flowchart
Go to “Power Up Troubleshooting”
on page 4-6
Go to “Front Panel Group
Troubleshooting” on page4-7
.
.
Go to “Measurement Group
Troubleshooting” on page 4-8
.
Service Guide N9912-90003 4-5
Troubleshooting RF Analyzer
Power Up Troubleshooting N9912A
Power Up Troubleshooting
If the display is operational but the unit does not boot up successfully into CAT mode:
• Make sure there is sufficient power for the unit to operate.
• Try re-installing firmware using the firmware upgrade process described in Chapter 8.
• Assume corrupted firmware on the A6 SOM board, follow the “Install Firmware from
SD Card” near the end of Chapter 7.
If the display is dark but the unit may have booted successfully:
• Wait for two minutes to make sure the boot process has completed, then press any front
panel key.
If the boot process has completed successfully, the keypad will flash when the key is
pressed.
4-6 Service Guide N9912-90003
RF Analyzer Troubleshooting
N9912A Front Panel Group Troubleshooting
Front Panel Group Troubleshooting
If no sound:
• Enter a value of just “.” (decimal point) for a frequency.
A double beep should occur. Plug headphones into the unit if there is no sound from the
internal speaker. The internal speaker is disabled when headphones are plugged in.
If the display is dark (no backlight):
• Press: Mode > System(7) > the left-most soft key > the next to the left-most soft key >
press the up arrow many times.
This should bring the display brightness setting to a viewable level.
Service Guide N9912-90003 4-7
Troubleshooting RF Analyzer
Measurement Group Troubleshooting N9912A
Measurement Group Troubleshooting
If calibration with the standard Type-N cal kit (1250-3607 or N9910X-800) gives
unexpected results:
• Make sure the unit is warmed up for at least 30 minutes.
• Make sure the correct cal kit definition is being used; erase user data to force use of
factory cal kit definitions (see Chapter 8 for information on the “Erase User Data
Utility”).
If there appears to be LAN communication problems:
• Use only 100 Base T LAN connections. Sometimes there are problems with the slower
speed 10 Base T connections.
If “ADC Overload” error messages are displayed during S21 or insertion loss
measurements:
• Perform the “ADC Overload Adjustment” under “Adjustments (Agilent N7841A
Software Package)” in Chapter 3.
4-8 Service Guide N9912-90003
5 Theory of Operation
Service Guide N9912-90003 5-1
Theory of Operation RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
This chapter provides a general description of the operating theory of the N9912A
analyzer.
• Theory of operation is explained to the assembly level only.
• Component-level circuit theory is not provided.
• Simplified block diagrams are included for each functional group.
Chapter Five at-a-Glance
Section Title Summary of Content Start Page
Analyzer System Operation A summary of the theory of operation for the
analyzer.
A summary of the operation of the major
functional groups of the analyzer.
Front Panel Group Operation of the assemblies associated with the
front panel group of assemblies.
Measurement Group Operation of the assemblies associated with the
measurement group of assemblies.
Operation in Modes Description of the different operating modes and
what hardware is used in each mode.
Temperature Related
Information
User Calibration in CAT and
NA Modes
Firmware Related Information Information about firmware and firmware
Information about temperature sensors and
how the analyzer responds to temperature
information gathered.
Descriptions of one port and two port
calibrations for the CAT and NA modes of
operation.
upgrades.
Page 5-3
Page 5-5
Page 5-7
Page 5-21
Page 5-25
Page 5-26
Page 5-28
5-2 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Analyzer System Operation
Analyzer System Operation
The N9912A RF analyzer operates as both a network analyzer (NA) and a spectrum
analyzer (SA). The NA functions support the CAT mode.
• The NA function supports one port measurements using the RF OUT port and two port
measurements using both the RF IN and RF OUT ports.
• The SA function supports measurements using the RF IN port.
See Figure 5-1 for a simplified block diagram of the overall RF analyzer system.
All N9912A RF analyzers have the same hardware. Options to increase functionality are
enabled via licenses, additional hardware is not required.
Functional Groups of the Analyzer
The operation of the analyzer can be separated into two major functional groups. Each
group consists of assemblies that perform distinct functions. Some of the assemblies are
related to more than one group, and both groups, to some extent, are interrelated and
affect each other's performance.
The major functional groups are:
• Front Panel Group
• Measurement Group
Front Panel Group
The front panel group consists of the following:
• A2 LCD Assembly
• A3 Front Panel Interface Board
Measurement Group
The measurement group consists of the following:
• A4 RF Board
• A5 System Board
• A6 SOM Board
• Main Battery
Service Guide N9912-90003 5-3
Theory of Operation RF Analyzer
Analyzer System Operation N9912A
Figure 5-1 Overall Block Diagram
5-4 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Front Panel Group
Front Panel Group
The front panel group consists of the following assemblies:
• A3 Front Panel Interface Board
• A2 LCD Assembly
Refer to Figure 5-1 for a simplified overall block diagram which includes the front panel
group.
A3 Front Panel Interface Board
The main function of the A3 front panel interface board is to support the user interface but
it also contains the digital power supplies.
Microcontroller and CPLD
The Microcontroller and CPLD sense the keypad keys and the RPG (rotary pulse
generator) knob on the front panel. The Microcontroller communicates with the A5 system
board via a USB interface.
There is no separate ID EPROM on the A3 front panel interface board. All ID information
is stored in the Microcontoller.
Front Panel LED’s and ON/OFF Button
The power for the Keypad LED’s generated on the A3 front panel interface board is derived
from the +5 V digital supply. The Keypad LED’s are turned on for a few seconds following
each key press. This function is controlled by the firmware on the A6 SOM board.
The On/Off LED is controlled by a signal from the A5 system board. The connections for
the On/Off Button and LED are direct to the A5 system board.
Real Time Clock Battery
The battery for the RTC (real time clock) on the A6 SOM board is located on the A3 front
panel interface board and is connected to the A6 SOM board via the A5 system board.
Backlight Power
Power for the backlight on the A2 LCD assembly is generated on the A3 front panel
interface board. Digital 5 volts is converted to approximately 25 volts. The actual voltage
determines the brightness of the backlight. Two control lines from the A5 system board
control on/off and intensity functions. These control lines are driven by the system monitor
microcontroller on the A5 system board.
Speaker and Headphones
The speaker is located on the A3 front panel interface board. Left and right audio signals
from the A6 SOM board go to the headphone jack on the A5 system board. These signals
are then combined (on the A5 system board) to create a single mono signal for the speaker.
An amplifier on the A3 front panel interface board drives the speaker. Plugging in the
headphones disables the speaker output.
Service Guide N9912-90003 5-5
Theory of Operation RF Analyzer
Front Panel Group N9912A
Digital Power Supplies
Digital power supplies on the A3 front panel interface board are driven by the Unreg DC
voltage from the A5 system board.
The 5 volts produced is used on the A3 front panel interface board and the A5 system
board.
The 3.5 volts produced is used on the A3 front panel interface board, the A5 system board,
and the A6 SOM board.
Both supplies are either on or off together except for power supply sequencing and are
controlled by the System Monitor Microcontroller on the A5 system board.
A2 LCD Assembly
The A2 LCD assembly contains a 6.5-inch, 640 x 480 TFT color LCD with associated drive
circuitry and backlight inverter.
The LCD backlight is created by LED’s connected in parallel stacks. Backlight brightness
is a function of the backlight power that ranges from 22 to 27 volts. Refer to “Backlight
Power” on page 5-5 for more information.
The backlight LED’s are arranged along the top and bottom edges of the display. There are
three stacks on each edge.
5-6 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Measurement Group
Measurement Group
The measurement group produces a stable output signal by phase locking a synthesized
voltage-controlled oscillator (VCO).
The measurement group consists of the:
• A4 RF Board
• A5 System Board
• A6 SOM Board
• Main Battery
A simplified RF block diagram is provided in Figure 5-2.
A simplified system block diagram is provided in Figure 5-3.
A4 RF Board
The basic function of the A4 RF board is to provide a signal source and receivers for the
analyzer functions.
There are three sections to the A4 RF board:
• the Common RF section,
• the CAT/NA RF section, and the
•SA RF section.
Common RF Section
This section is common to both NA and SA functions. In this common section, an LO
synthesizer produces a single LO signal from the 30 MHz time base located on the A5
system board. The LO output is switched between the NA mixers and the SA first
converter depending on the function being used. At any instant in time, either the NA
receivers or the SA receiver may be active, but not both at the same time.
The LO frequency bands are listed below:
1 100 kHz to 1.6 MHz
2 1 .6 MHz to 25 MHz
3 25 MHz to 0.2 GHz
4 0.2 GHz to 0.8 GHz
5 0.8 GHz to 1.6 GHz
6 1.6 GHz to 3.2 GHz
7 3.2 GHz to 3.4 GHz
8 3.4 GHz to 4.15 GHz
9 4.15 GHz to 5.1 GHz
10 5.1 GHz to 6.2 GHz
Service Guide N9912-90003 5-7
Theory of Operation RF Analyzer
Measurement Group N9912A
Figure 5-2 Simplified RF Block Diagram
5-8 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Measurement Group
CAT/NA RF Section
In this section, the 30 MHz time base from the A5 system board is used to generate a
source signal in the source synthesizer that covers the frequency range of 100 kHz to
6.2 GHz.
The source signal is generally rich in harmonic content. This is acceptable because the
signal is used with tuned receivers.
The source frequency bands are listed below:
1 100 kHz to 1.6 MHz
2 1.6 MHz to 25 MHz
3 25 MHz to 0.2 GHz
4 0.2 GHz to 0.8 GHz
5 0.8 GHz to 1.6 GHz
6 1.6 GHz to 3.2 GHz
7 3.2 GHz to 6.2 GHz
The RF Out attenuator between the source and the reflectometer has two settings:
nominal values of 0 dB and 30 dB. The setting is determined by the Hi/Lo power setting on
the user interface.
The reflectometer performs three functions:
• It passes the source output signal to the RF OUT port.
• It samples the source output to the RF OUT port.
• It samples the incoming signal at the RF OUT port.
The sampled signals are mixed with the LO signal to produce two 290 kHz IF signals,
NA-A and NA-R.
The reflectometer dissipates up to 1.5 watts when active.
The RF OUT port has a DC isolation capacitor (0.056uF).
SA RF Section
In this section, the signal at the RF IN port is first routed through a DC isolation capacitor
(0.056 uF) then through the RF In attenuator.
RF In Attenuator The RF In attenuator covers the range of 0 dB to 31 dB in one dB
steps. An adjustment determines compensation for each of the 32 steps over 11 frequency
bands (see “SA Frequency Bands” on page 5-10).This compensation provides nominal 1.0
dB steps.
Pre-Amp The pre-amp that follows the RF In attenuator may be in or out during the SA
mode. Option 235 is required for the firmware to enable use of this pre-amp. The pre-amp
is always bypassed in CAT and NA modes.
Typical gain of the pre-amp is 22 dB. It has two sections, high-band and low-band. The
low-band section covers up to 2.7 GHz.
Service Guide N9912-90003 5-9
Theory of Operation RF Analyzer
Measurement Group N9912A
Converters Three stages of conversion produce the 37.5 MHz SA IF signal that goes to
the A5 system board.
The first converter stage mixes the incoming signal with the LO output. Input signals
below 2.7 GHz are up converted and input signals above 2.7 GHz are downconverted.
Spur avoidance is accomplished by slightly shifting the output frequency of the first
converter stage. When the output frequency of the first converter is shifted, the second
converter compensates for the shift.
The third converter output frequency is fixed at all times.
SA Frequency Bands The frequency bands for the SA function are as listed below:
Up to 2.7 GHz (bands 1-4) are considered LOW bands and above 2.7 GHz (bands 5-11) are
considered HIGH bands. Different hardware is used for each type.
Analyzer
Band
Start Frequency
(MHz)
1 0.000 10.000
2 30.000 715.000
3 715.000 1665.000
4 1665.000 2700.000
5 2700.000 3313.500
6 3313.500 3500.000
7 3500.000 4263.500
8 4263.500 4300.000
9 4300.000 5200.000
10 5200.000 5936.500
11 5936.500 6000.000
Analyzer
Stop Frequency
(MHz)
Power Management Circuitry
The circuitry on the A4 RF board has five special sections that may be powered down for
the purpose of power management. These sections may be selectively powered down (via
“load switching”) when not required for the current operating mode of the analyzer.
The sections that may be selectively powered down are:
• Source—most of the source synthesizer circuitry
• LO—most of the LO synthesizer circuitry
• SA—most of the first, second, and third converter circuitry
• Reflectometer—put into a low power state
• High-Band Pre-amp—high band section of the pre-amp turned off
The load switching for the Source, LO, and SA sections is accomplished on the A5 system
5-10 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Measurement Group
board via the Analog Power Supply Load Switching circuitry.
The load switching for the Reflectometer and High-Band Preamp is accomplished on the
A4 RF board.
Other Circuitry
The CPLD (Complex Programmable Logic Device) communicates wit5h the FPGA on the
A5 system board via Serial Bus [A]. It provides the digital control for the functions on the
A4 RF board. It also reads the VCO unlock signals.
Serial Bus [B] allows the System Monitor on the A5 system board to read two temperature
sensors and the ID EPROM for the A4 RF board.
RF1 temperature sensor (NA Temp Sensor) is near the RF OUT connector on the side of
the A4 RF board that is away from the A5 system board. This temperature sensor is
nearest the NA circuitry.
RF2 temperature sensor (SA Temp Sensor) is located through the A4 RF board from
FL1202 on the A5 system board side of the A4 RF board. This temperature sensor is
nearest the SA circuitry.
Service Guide N9912-90003 5-11
Theory of Operation RF Analyzer
Measurement Group N9912A
A5 System Board
The A5 system board controls all of the functions of the analyzer and digitizes the RF IF
signal from the A4 RF board.
The A6 SOM (System on Module) board is mounted directly on the A5 system board.
All external connections for the analyzer come through the A5 system board except for the
RF IN and RF OUT ports.
The A5 system board also controls the power switching and power management.
The instrument model number and serial number are stored on the A5 system board.
System Monitor (SM) Microcontroller
This is the heart of the analyzer. It is active whenever there is DC power available. The
microcontroller has ultra-low power dissipation. It is sometimes referred to as the
“MSP 430”.
The following is a list of some of the functions performed by the SM.
• It monitors the On/Off button on the front panel and responds appropriately.
• It controls the on/off functions of the various power supplies in the analyzer.
• It drives the On/Off button LED.
• It reads battery pack information via the Smart Batt Bus.
• It communicates with the battery charger IC via the Smart Batt Bus.
• It interfaces to the Battery Charger and Manager circuit.
• It interfaces to the Serial Bus [B] for communication with the temperature sensors and
ID EPROM’s on the printed circuit boards.
• It communicates to the A6 SOM board CPU via a serial port, UART.
• It stores the instrument model number and serial number.
Battery Charger and Manager
This circuitry controls charging of the battery based on a battery charger IC. This IC is
powered by a digital output on the System Monitor. The System Monitor has the capability
to reset the IC, if required, by recycling the power to the IC.
This circuitry also controls the source of the Unreg DC: Batt or Ext DC. It reads the
battery pack information via the Smart Batt Bus. Batt Neg is connected to the A5 ground
plane.
There is an input inrush current control circuit on the Ext DC input that limits inrush
current to 4 amps.
Analog Power Supplies and Load Switching
Seven different analog supply voltages are generated from the Unreg DC. All of these are
used on the A4 RF board and some are used on the A5 system board.
Some sections of the circuitry on the A4 RF board may be switched to low power modes to
5-12 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Measurement Group
conserve power and minimize heat. This is accomplished through load switching. See
“Power Management Circuitry” on page 5-10 for more information.
The System Monitor controls the on/off functions of the analog power supplies. All are on
or off together except for power sequencing.
This circuitry also monitors the Ext DC input and, if below 10.8 volts or above 21 volts, it
disconnects this input from the Unreg DC.
There are two DC power supply lines: (1) Ext DC, and (2) Batt +. Each has a 5 amp fuse
immediately after the connector on the printed circuit board.
FPGA
This FPGA:
• provides the interface between the A6 SOM board and the ADC,
• provides miscellaneous interfaces for circuitry on the A4 RF board, and
• communicates with the CPU via the USB interface.
Time Base
The Time Base is an internal TCXO that produces 30 MHz signals for use throughout the
analyzer.
A 10 MHz signal at the EXT TRIG/EXT REF input may be used to provide and external
time base. The external time base function is controlled via the user interface. Refer to the
“External Frequency Reference” section of the FieldFox User’s Guide for additional
information.
There is no external trigger (EXT TRIG) function at the time of this printing.
Filters, MUX, and ADC’s
The three Filters filter the IF signals in preparation for the ADC. Filter characteristics are
fixed (not programmable).
The ADC’s digitize each of the IF signals received from the A4 RF board. The input to one
of the ADC’s is multiplexed between the NA-A and SA input signals. Since the NA-R and
NA-A signals are sampled simultaneously, phase relationship is preserved.
The 14-bit ADC’s sample at a rate of 30 mega samples per second.
Each ADC may be put into a low power mode when not active.
Temperature Sensors
The SB1 Temp Sensor is located on the A4 RF board side of the A5 system board near the
headphone jack (J3).
The SB2 Temp Sensor is on the A4 RF board side of the A5 system board near the edge of
the board against the battery compartment. This temperature sensor is not under a shield.
Audio Output Jack
When headphones are plugged into the audio output jack, the internal speaker is disabled.
Service Guide N9912-90003 5-13
Theory of Operation RF Analyzer
Measurement Group N9912A
LAN Connector
The LAN connector supports the LAN interface on the A6 SOM board. See “LAN Interface”
on page 5-30 for more details.
SOM Connector
Refer to “A6 SOM Board” on page 5-16 for information on SOM (System on Module)
functions.
5-14 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Measurement Group
Figure 5-3 Simplified RF Block Diagram
Service Guide N9912-90003 5-15
Theory of Operation RF Analyzer
Measurement Group N9912A
A6 SOM Board
The A6 SOM (System on Module) board plugs directly into the A5 system board as a
daughter board and contains:
•the CPU,
• 64 MB of flash ROM,
• 128 MB of RAM, and
• I/O interface.
The interfaces on the SOM are:
• UART to the System Monitor on the A5 system board
•LCD interface
• Left and right audio outputs
•SD card bus
•USB host interface
• Interface to USB hub
• LAN interface 10/100 base T
• General purpose interface lines
The A6 SOM board is powered by the 3.3 volt digital supply.
Licenses which enable instrument options are stored in the A6 SOM flash ROM.
Main Battery
The battery is a rechargeable 10.8 V lithium-ion type. Refer to “Battery Disposal” on
page 1-7 for important information about replacing and disposing of this battery.
Refer to “Battery Related Information” on page 5-19 for details on the main battery.
5-16 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Grounding and Power
Grounding and Power
Grounding
Each printed circuit board has a single ground plane. The ground planes on the A4 RF
board and A5 system board are connected via the common shields at multiple points. The
ground plane on the A3 front panel interface board is connected to the ground plane on the
A5 system board.
There are no separate grounds in the analyzer. There is no “star” ground point in the
analyzer.
Batt Neg and Ext DC neg are connected to the A5 system board ground plane.
The A2 LCD assembly has two separate grounding circuits: the LCD power and control
circuits and the backlight LED’s.
• The LCD power and control circuits share a ground that is connected to the ground
plane on the A5 system board.
• The ground for the backlight LED’s is connected to the ground plane on the A3 front
panel interface board.
Voltages and Power Supplies
The following power supplies exist within the analyzer:
• Digital 5 volts—generated from Unreg DC on the A3 front panel interface board,
controlled by the System Monitor on the A5 system board, and used on the A3, A4, and
A5 boards.
• Digital 3.3 volts—generated from Unreg DC on the A3 front panel interface board,
on/off functions controlled by the System Monitor on the A5 system board, and used on
the A2 LCD assembly and A3, A4, A5, and A6 boards.
• Analog supply voltages—seven separate voltages generated from Unreg DC on the A5
system board, on/off functions controlled by the System Monitor on the A5 system
board.
• LCD backlight voltage—generated on the A3 front panel interface board from the
digital 5 volt supply voltage.
• Power for the System Monitor circuit—3.3 volt circuit powered from Ext DC or Batt +,
whichever is greater. Used on A5 system board only.
• Unreg DC—from Ext DC or Batt +, 21 volts max.
• Ext DC—from external Power AC Adapter, nominal 15 volts, acceptable up to 19 volts.
• Batt + —from main battery, nominal 12 volts.
All voltages except Ext DC, Batt +, and the System Monitor power can be turned on/off
within the analyzer. Refer to “Power Management Circuitry” on page 5-10 for more
information.
Service Guide N9912-90003 5-17
Theory of Operation RF Analyzer
Grounding and Power N9912A
Power Control and Management
Power States
The On/Off Button is used to switch between On, Off, and Standby power states:
Off Only the System Monitor and battery control circuits are powered up (if power is
available from the battery or external power).
If the battery is charging, the LED below the On/Off Button slowly flashes orange with
increasing intensity, otherwise this LED is off.
Some battery power is required in the “Off” state. A fully charged battery will discharge
completely in four to six weeks when left in the analyzer.
On This is normal operation. The On/Off Button LED is steadily lit green.
Standby Only the digital power supplies are on. The CPU is in a low power state,
maintaining RAM content. The On/Off Button LED flashes yellow briefly every two
seconds.
During normal operation, unexpectedly disconnecting power to the analyzer (such as
removing the main battery when the analyzer is not connected to external power) should
not cause any problems. Simply re-apply power. No firmware problems are expected. Of
course, this does not apply during a firmware upgrade.
Smart Power Management
The analyzer uses extensive “load switching” to minimize power dissipation. This is
termed Smart Power Management (SPM). There are two motivations for power
management:
• to extend battery run time
• to prevent overheating.
Sections of the circuitry are selectively powered down via “load switching”, depending on
the operating mode of the analyzer. Five different sections of the circuitry on the A4 RF
board may be controlled via “load switching”. These sections are as follows:
• Source—switched off during SA mode, switched off between sweeps during CAT or NA
modes.
• LO—switched off when data is not being taken by receivers.
• SA—switched off when in one port CAT or NA modes, on all the time in two port mode.
• Reflectometer—switched to low power through state when RF OUT port receivers are
inactive.
• High-Band Pre-amp—switched off when not required.
On the A5 system board, each of the ADC’s may be individually switched to a low power
mode when not active.
Load switching is generally transparent to the user. One obvious exception is the that the
source turns off during “retrace” in the CAT and NA modes.
5-18 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Grounding and Power
Battery Related Information
Battery Description and Operation
The main battery is an SBS (Smart Battery System) compliant pack of lithium ion cells.
Refer to “Battery Disposal” on page 1-7 for important information about replacing and
disposing of this battery.
The nominal voltage of the battery is 10.8 volts and normally varies from 9 to 12 volts.
The battery has built-in sensors, a processor, and control circuitry. This is referred to as
the Smart Battery circuitry.
The Smart Battery circuitry communicates battery condition and history information
digitally via a digital Smart Batt Bus. The Smart Battery circuitry is read-only.
Both the battery charging circuit and the System Monitor read battery information over
the Smart Batt Bus.
The battery temperature reported by the analyzer is based on a sensor inside the battery.
Temperature information is available over the Smart Batt Bus. The thermistor connection
(T) on the battery is not used.
The Smart Battery circuit may shut down the battery when the temperature is out of the
acceptable range or when the battery charge is too low.
See the “Working with the Lithium-Ion Battery” section of the FieldFox User’s Guide for
additional information on:
• built in charge level gauge
• the battery information screen
• battery care
Battery Information Screen
Refer to the FieldFox User’s Guide for information on how to access this screen.
Most of the items displayed on the screen come directly from the battery via the Smart
Batt Bus. Only the first three items are influenced by the analyzer.
Battery Charging Management
The battery pack determines when the battery needs charging and requests a charge over
the Smart Batt Bus.
The Battery Charger and Manager circuit on the A5 system board responds by charging
the battery if there is sufficient voltage on the Ext DC line. A minimum of approximately
15 volts is required to charge the battery.
The System Monitor on the A5 system board monitors the battery’s temperature and, if too
high or too low, disables charging of the battery.
How to tell if the battery is charging:
• If the analyzer is On, the lightening bolt is displayed in the battery icon.
Service Guide N9912-90003 5-19
Theory of Operation RF Analyzer
Grounding and Power N9912A
• If the analyzer is Off, the LED below the On/Off Button slowly flashes orange with
increasing intensity.
• If the analyzer is in Standby, turn the analyzer on and observe the battery icon.
The battery charges much faster up to 70% of its full charge than it does above 70% of full
charge.
Battery Life
When a battery is new, an instrument should operate for about four hours on a fully
charged battery. The actual time will depend on operating mode and temperature.
As a battery goes through charge/discharge cycles, its capacity will decrease. A typical
battery will have more than 70% of its initial capacity after 200 full discharge cycles when
operating at 20 to 30 ° C ambient temperature.
5-20 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Operation in Modes
Operation in Modes
The FieldFox User’s Guide describes the various modes of operation and describes the user
interface for each mode. The following information describes how the hardware is used in
the various modes to make measurements.
There are four basic modes of operation:
• CAT—Cable and Antenna Test
• NA—Network Analyzer
• SA—Spectrum Analyzer
• PM—Power Meter
CAT and NA modes have similar capabilities but are separate modes of operation.
Additional modes of operation may be created as new firmware is developed. The four basic
modes listed above represent how the hardware may be used to make basic measurements.
Additional modes will provide customized user interfaces but will not change how the basic
measurements are performed.
The following table indicates port functionality for each mode of operation and the
required options. See the “Service Related User Operations” section of Chapter 8 for more
details.
Table 5-1. Port Function by Mode
Measurement
Mode
CAT
(One Port)
CAT
Insertion Loss
NA
S11
NA
S21
SA Inactive Input 230 or 231
Power Meter Inactive Inactive 302
RF OUT
Port
Input/Output Inactive
Output Input 110
Input/Output Inactive 303
Output Input 110 and 303
RF IN
Port
Required
Option(s)
None
(standard)
For a given mode, the analyzer “remembers” the most recent state of the current mode
when you change to another mode.
For most screens under System 7 key, the current measurement mode continues to operate
while the screen is displayed. For instance, while the battery information screen is
displayed, the measurement mode remains active.
There are two exceptions to this:
• the “Options (Licensing)” screen
• “Error Log” screen
Service Guide N9912-90003 5-21
Theory of Operation RF Analyzer
Operation in Modes N9912A
When either of these screens is displayed, the firmware is in a special monitor mode and
measurements are suspended.
CAT and NA Modes
CAT and NA modes have some similar capabilities but are still separate operating modes.
Measurement similarities:
• Return Loss = S11 magnitude
• Insertion Loss = S21 magnitude
Unlike S11 and S21, the values displayed below zero for Return Loss and Insertion Loss
are not negative.
Measurements are done at an effective IFBW (IF bandwidth) of 30 kHz except when max
for Interference Rejection measurements when it is at a 300 Hz effective IFBW.
There is no user control of the output power level of the source synthesizer on the A4 RF board.
The only user control of output power level is the high/low setting on the RF Out Atten,
30 dB in or out.
Details About One Port Measurements
Refer to the block diagram below showing the signal paths highlighted in color.
Figure 5-4 Signal Paths for One Port CAT/NA Measurements
5-22 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Operation in Modes
The source and receiver step through each frequency point in the sweep.
Single sweep measures both NA-A and NA-R signals. Because two ADC’s are used
simultaneously, phase relationship is preserved. (Phase information is available to the
user only in NA mode.)
Details About Two Port Measurements
Refer to the block diagram below showing the signal paths highlighted in color.
Figure 5-5 Signal Paths for Two Port CAT/NA Measurements
The RF IN port is used as the second port.
Two sweeps are required for a measurement: one sweep for the NA-R signal and a second
sweep for the SA signal. Because of the shared LO and A/D, no phase relationship is
available, only magnitude.
Service Guide N9912-90003 5-23
Theory of Operation RF Analyzer
Operation in Modes N9912A
When measuring the SA signal, the source and SA receiver step through each frequency
point in the sweep. (The SA receiver is effectively in step mode and tuned to the source
frequency.)
The SA Pre-amp is always switched out.
The RF In Atten is not under user control. For a given frequency, the ADC Overload
Adjustment determines the setting for this attenuator to prevent over-range warnings.
There is no default calibration for two port measurements. Uncalibrated (not normalized)
measurement of a short thru cable typically shows a trace with some sawtooth
characteristics.
SA adjustment results are ignored when in CAT/NA mode. T he “raw” unadjusted readings
are used. There is one exception: the results of the IF Offset Adjustment are used during
CAT/NA modes.
SA Mode
The signal path for SA mode is the same as the input path for two port CAT/NA modes.
The RF In Atten can be set to 32 different levels: nominal 0 through 31 dB in 1 dB steps.
The Attenuator Slope Adjustment determines the correction factors for each step in each
frequency band.
The RF In Atten can be controlled manually or automatically. When in auto mode, the
Reference Level setting determines the attenuator setting.
The Pre-amp can be in or out. Nominal gain of the pre-amp is 22 dB.
The “Attn” and “PA” indicators in the display header give current status. The Scale/Amptd
hard key provides access to control for them.
The displayed measured value for a given signal is automatically compensated for in the
current Attn and PA settings. For instance, if an incoming signal is measured at -70 dBm
with the RF IN Atten set to 5 dB and PA “out”, changing to PA “in” will give a measured
value of approximately -70 (+/- because the 22 dB for the PA is only nominal). The
difference seen in the trace will be that the noise floor of the trace will be lowered by
approximately 22 dB. If the RF In Atten is changed from 5 dB to 15 dB, the measured
value will not change significantly (still approximately -70 dBm) but the noise floor will
raise by 10 dB.
SA has two basic modes: step and FFT.
Step mode reads a narrow slice of the spectrum and the LO steps for each slice. In this
mode, a trace on the display is composed from multiple slices. Generally spans greater
than 100 kHz operate in step mode.
FFT mode reads a wide slice of the spectrum and the LO is fixed. In this mode, a trace on
the display is based on a single LO setting.
The LO minimum step size is 2 MHz; this restriction limits spurs.
The hardware operation of the A/D’s is essentially the same for both step and FFT modes.
The difference is the digital signal processing.
The SA adjustments generally correct the gain with 11 frequency bands. See “SA
5-24 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Temperature Related Information
Frequency Bands” on page 5-10 for a listing of the 11 bands. See the TME help file for
details on SA adjustments.
Power Meter Mode
All measurement circuitry is switched to the low power state during PM (power meter)
mode. This is the mode with the lowest power dissipation.
The analyzer has no power output capability in this mode. The analyzer essentially
functions as a display for a USB power sensor.
Temperature Related Information
Five temperature sensors are in the analyzer: two on the A4 RF board, two on the A5
system board, and one in the battery pack.
• RF1—NA Temp Sensor (on the A4 RF board near the NA circuitry)
• RF2—SA Temp Sensor (on the A4 RF board near the SA circuitry)
• SB1—on the A5 system board near the headphone jack
• SB2—on the A5 system board near the battery compartment
• Battery pack—inside the battery pack
The battery pack has its own internal temperature sensor. The battery pack will shut itself
down in the case of extreme temperatures.
See Chapter 8 for instructions on viewing temperature readings.
See the FieldFox User’s Guide, “FieldFox High-Temperature Protection” section, for
information about operation at high temperature.
The temperature readings for sensor RF2 are stored as part of the adjustment data for the
Frequency Response Preamp On/Off adjustments.
During normal operation, as each SA measurement is taken, the current RF2 temperature
reading is compared tot he temperature stored for the Frequency Response adjustment. A
delta temperature is calculated. Each SA measurement is adjusted to compensated for the
delta temperature.
The internal temperature of the unit is critical when executing the TME based software for
tests and adjustments. See the TME help for detailed information.
Under typical bench top (indoor) conditions, the internal temperature of the unit will be
about 20 ° C above ambient once the internal temperature has stabilized. It will typically
take 60 to 90 minutes for the internal temperature to stabilize when a “cold” unit is turned
on.
Service Guide N9912-90003 5-25
Theory of Operation RF Analyzer
User Calibration in CAT and NA Modes N9912A
User Calibration in CAT and NA Modes
There are two types of calibrations for the CAT and NA modes: one port and two port. See
the FieldFox User’s Guide “Calibration for CAT and NA Modes” section for specific
instructions for performing these calibrations. A calibration performed in CAT mode will
be applied in NA mode and vice versa.
When a user calibration is performed, the full frequency range of the analyzer is calibrated
even though the current state of the analyzer may be less than the full range. This allows a
calibration to be “interpolated” beyond the frequencies set at the time of calibration (an
asterisk “*” on the display indicates interpolation).
When choosing the “Connector Type”, choose the characteristics that correspond to the cal
kit you will use. For the standard FieldFox Tee cal kit, part number 1250-3607, choose
“Type-N–M-”.
Do not leave cal standards connected to the RF IN or RF OUT ports for more than three
minutes. Heat in the port connectors may affect the accuracy of the standards.
Table 5-2. Cal Status Indicators
Indicator Meaning Additional Indicators
Cal ON Preset (factory) calibration is active
Cal ON Q QuickCal calibration is active
Cal ON U O, S, L calibration is active
Cal OFF Calibration is inactive
Cal OFF*
No calibration available to activate
for this measurement.
* = interpolation active
? = Measurement conditions have changed.
* = interpolation active
? = Measurement conditions have changed.
* = interpolation active
? = Measurement conditions have changed.
One Port Calibration
One port calibration applies only to 1-port measurements in CAT and NA modes. When the
analyzer is adjusted at the factory or during annual calibration, a preset calibration is
stored in the analyzer.
The preset calibration covers the full frequency range of the analyzer. The preset
calibration is active whenever “Cal ON” is displayed on the left side of the screen.
Presetting the analyzer activates the preset calibration.
The preset calibration provides very good measurement performance at the RF OUT
connector when the analyzer has thermally stabilized to room temperature. Operation at
other temperature conditions may impact measurement accuracy when applying the
preset calibration.
The preset calibration should be re-characterized every 12 months to maintain accuracy.
This is accomplished via the Error Terms test/adjustment in the TME. Refer to Chapter 3.
5-26 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A User Calibration in CAT and NA Modes
Under ideal conditions, a preset calibration and an OSL (open, short, load) calibration
should give very similar results for measurements at the RF OUT port.
Two Port Calibration
Two port calibration applies only when S21 or Insertion Loss measurements are active.
There is no “built-in” or “preset” two port calibration in the analyzer. A normalize
calibration must be performed before making two port measurements.
QuickCal
The QuickCal function mathematically “extends” the preset calibration to the end of a
cable or adapter. It is a firmware only function; it does not involve analyzer hardware.
Service Guide N9912-90003 5-27
Theory of Operation RF Analyzer
Firmware Related Information N9912A
Firmware Related Information
General Description
The analyzer is based on the Windows CE1 operating system. This is a closed system; no
direct user access to the desktop of general operating system functions is provided.
The file system for Windows CE is maintained in flash memory on the A6 SOM board.
There is limited access to the file system. Most memory is in protected region and not
directly accessible by the user.
The user accessible memory is under UserData. See the “File Management” section of the
FieldFox User’s Guide for instructions on saving, recalling, and managing files in the
unprotected memory.
User Accessible Files
• Directory structure below UserData in the A6 SOM board flash memory (approximately
20 MB).
• External USB flash memory plugged in the analyzer.
• External SD memory card plugged into the analyzer.
NOTE: When copying files, a “Copy_....” directory is created at the root of the destination
device as the destination for the copied file(s). This characteristic generally makes it
impossible to copy a file into the desired directory under UserData in the A6 SOM board
flash memory. This limits the usefulness of copying files to or within UserData.
Operational Files
• Results from adjustments performed under TME (see Chapter 3)—not directly available
to user.
• File resulting from CAT/NA user calibration—not directly available to user.
• Cal kit definition files—stored in UserData\calkits.
• Cable definition files—stored in UserData\Cables.
• Error log—not directly available to user. See “Error Log” further on in this section for
accessing error log information.
Erase User Data Utility
A utility to erase all directories and files in the UserData directory is available. After the
flash memory is erased, the boot process returns the UserData directories and files to the
state as shipped from the factory. The System Information screen indicates the time and
date of the most recent erase.
See Chapter 8 for instructions on executing the Erase User data utility.
1. Windows® and Windows CE® are U.S. registered trademarks of Microsoft Corporation.
5-28 Service Guide N9912-90003
RF Analyzer Theory of Operation
N9912A Firmware Related Information
Error Log
See Chapter 8 for instructions on viewing the error log.
The error log is cleared each time the analyzer is powered off.
Generally, an entry in the error log is created whenever an error message is displayed.
EXAMPLE: Attempting to set the frequency to a value of “.” (a decimal point), will
generate an entry in the error log.
Firmware Upgrades
Firmware upgrades are available on the Internet. Refer to instructions in the “Update
FieldFox Firmware” section of the FieldFox User’s Guide for details.
See Chapter 8 for instructions on viewing the current firmware revision.
The following information will be included in the display.
• Firmware Release = FieldFox application firmware revision
• FPGA Rev = code revision for FPGA
• SBM Boot Rev = revision of boot code for System Microcontroller
• SBM Main Rev = revision of main code for System Microcontoller
A firmware upgrade includes three sections:
• the FieldFox application firmware and the Windows CE operation system on the
A6 SOM board.
• the firmware in the System Monitor Microcontroller on the A5 system board.
• the FPGA code on the A5 system board.
The System Monitor firmware update and the FPGA code update are executed only if not
up-to-date.
It is important to maintain power to the analyzer during the update process.
After unplugging the USB flash memory stick during the firmware upgrade process, wait
for the analyzer to activate the CAT mode before operating the analyzer.
Service Guide N9912-90003 5-29
Theory of Operation RF Analyzer
LAN Interface N9912A
LAN Interface
See the “System Configuration” section of the FieldFox User’s Guide for details on
reviewing and configuring LAN settings.
Currently the LAN interface supports only communication for the Data Link software and
sending SCPI commands for service purposes.
The LAN interface supports Auto MDIX. When a LAN cable is connected to the FieldFox, if
the other end of the cable supports Auto MDIX, there is no need for a cross-over cable.
There are two LEDs on the LAN connector. When there is successful communication over a
LAN cable, both LEDs are active. If both LEDs are not active, consider using a cross-over
cable.
5-30 Service Guide N9912-90003
6 Replaceable Parts
Service Guide N9912-90003 6-1
Replaceable Parts RF Analyzer
Information in This Chapter N9912A
Information in This Chapter
This chapter:
• identifies the replaceable parts for the N9912A RF analyzer.
• includes several tables and illustrations to assist you in identifying the correct part for
your analyzer.
• contains ordering information for new assemblies and rebuilt-exchange assemblies.
Chapter Six at-a-Glance
Section Title Summary of Content Start Page
Ordering Information
Assembly Replacement
Procedure
Replaceable Parts Listings
How to order a replaceable part from Agilent
Technologies.
The correct sequence for determining the failure
of and replacing a defective assembly.
Tables with illustrations that list all replaceable
parts in your analyzer:
Page 6-3
Page 6-4
Page 6-5
6-2 Service Guide N9912-90003
RF Analyzer Replaceable Parts
N9912A Ordering Information
Ordering Information
To order a part listed in the replaceable parts lists:
• include the part number
• indicate the quantity required
• Contact Agilent Technologies for instructions on where to send the order. Refer to
“Contacting Agilent” on page 2-5.
To order a part that is not listed in the replaceable parts lists:
• include the instrument model number and complete instrument serial number
• include the description and function of the part
• indicate the quantity required
• Contact Agilent Technologies for instructions on where to send the order. Refer to
“Contacting Agilent” on page 2-5.
Service Guide N9912-90003 6-3
Replaceable Parts RF Analyzer
Assembly Replacement Procedure N9912A
Assembly Replacement Procedure
The following steps describe how to replace an assembly in the analyzer.
Step 1. Identify the faulty group. Begin with Chapter 4, “Troubleshooting.” Follow up
with the appropriate troubleshooting chapter that identifies the faulty assembly.
Step 2. Order a replacement assembly. Refer to this chapter for part numbers and
ordering information.
Step 3. Replace the faulty assembly and determine what adjustments and performance
tests are necessary. Refer to Chapter 7, “Repair and Replacement Procedures.”
Step 4. Perform the necessary adjustments. Refer to Chapter 3, “Tests and Adjustments.”
Step 5. Perform the necessary performance tests. Refer to Chapter 3, “Tests and
Adjustments.”
6-4 Service Guide N9912-90003
RF Analyzer Replaceable Parts
N9912A Replaceable Parts Listings
Replaceable Parts Listings
Entire Analyzer
Figure 6-1 Entire Analyzer, Exploded View
Descriptions and part numbers for the assemblies and parts in each group shown in the
above illustration can be found at the following locations:
• “Front Panel Group” on page 6-6
• “Measurement Group” on page 6-8
• “Case Group” on page 6-10
Miscellaneous parts and accessories not illustrated in any of these groups are listed under:
• “Miscellaneous Parts” on page 6-12
Service Guide N9912-90003 6-5
Replaceable Parts RF Analyzer
Replaceable Parts Listings N9912A
Front Panel Group
Reference
Designator
Replacement Assemblies
A3 Front
Panel Board
Assembly
Separately Replaceable Individual Parts and Assemblies
A1
A2 2090-0968 1 LCD assembly, 6.5-inch TFT VGA
(1)
(2) N9912-00001 1 LCD shield (bracket)
(3) 0515-1521 13 Screw, machine, 90-deg flat head, M3.0 x 5 mm
(4) 1990-3613 1 RPG (Rotary Pulse Generator). Includes cable W12, nut, and washer.
(5) W1312-40066 1 R PG knob
Part Number Qty Description
N9912-60003 1
Keypad assembly (P art of Front Enclosure Assembly and not separately replaceable; see “Case
Group” on page 6-10.)
LCD lens filter (Part of Front Enclosure Asse mbly and not separately replaceable; see “Case
Group” on page 6-10.)
1
Front Panel Board Assembly—Includes:
A3 front panel interface board
(6) N9912-60017 1 Cable W13, A2 LCD to A3 front panel interface board
(7) N9912-60006 1 Cable W14, ribbon, A3 front panel interface board to A5 system board
(8) N9912-60016 1 Cable W11, A2 LCD to A5 system board
(9) N9912-20035 1 Gap pad, LCD shield
(10) N9912-20038 1 Gap pad, LCD shield
(11) 1420-0536 1 Battery, Lithium-ion (For Real Time Clock (RTC) backup.)
1. Each time the N9912A case is opened for any reason, you must order a Repair and Re-assembly Kit.
See “Miscellaneous Parts” on page 6-12.
6-6 Service Guide N9912-90003
RF Analyzer Replaceable Parts
N9912A Replaceable Parts Listings
Figure 6-2 Front Panel Group, Exploded View
Service Guide N9912-90003 6-7
Replaceable Parts RF Analyzer
Replaceable Parts Listings N9912A
Measurement Group
1
Reference
Designator
Part Number Qty Description
Replacement Assemblies
RF Assembly—Includes:
A4 RF board
System gasket kit assembly, 2 gaskets (1)
Polyiron (mixer house), w/pad (2)
RFI wafer gasket, qty 2 (3)
Insulator, qty 2 (4)
Polyiron, front end (5)
Polyiron, pre-amp (6)
RF
Assembly
System
Board
Assembly
Coax
Cable
Assembly
RF
Top Panel
Assembly
N9912-60002 1
N9912-60004 1
N9912-60029 1
N9912-60021 1
Polyiron, input (7)
Shield, bottom, RF (8)
Shield, top, RF (9)
Cable W2, semi-rigi d, RF IN (SA port) (10)
Cable W1, semi-rigi d, RF OUT (NA port) (11)
Gap pad, 6 mm square (12)
RFI O-ring, qty 2 (13)
RFI strip, qty 4 (14)
Adapter, coaxial, straight, female type-N to female 3.5 mm, qty 2 (15)
Screw, m achine w/crest cup washer, pan head, M3.0 x 12 mm, qty 30 (16)
Screw, machine w/crest cup washer, pan head, M3.0 x 8 mm, qty 4 (17)
System Board Assembly—Includes:
A5 system board
System gasket kit assembly, 2 gaskets (1)
Clamp, stick- on, qty 2 (18)
Coax Cable Assembly—Includes:
Cable W4 and W6, RF, flexible, qty 2 (19)
Spiral wrap, plastic (20)
RF Top Panel Assembly—Includes:
Panel, RF, machined (21)
Connector cover (tethered cap), for type-N connect or, qty 2 (22)
Overlay, RF (23)
Gasket, RF (24)
Cable W3, RF coax with BNC connector, EXT TRIG/EXT REF connector (27)
Washer, internal tooth, 15/32-inch (28)
Nut, specialty, 15/32-inch - 32 thread (29)
Separately Replaceable Individual Parts and Assemblies
A6 1150-8023 1 SOM Board, 532 MHz processor, 128 MB-SDRAM
(1) N9912-60019 1 System gasket assembly, 2 gaskets for A5 system board
(4) N9912-20033 1 Insulator, w/pad
(10) N9912-20010 1 Cable W2, semi-rigi d, RF IN (SA port)
(11) N991 2-20009 1 Ca ble W1, semi-rigid, RF OUT (NA port)
(13) 8160-0963 2 RFI O- ring
(15) 1250-2180 2 Adapter, coaxial, straight, female type-N to female 3.5 mm
(17) 0515-0372 4 Screw, machine w/crest cup washer, pan head, M3.0 x 8 mm
(22) W1312-40069 2 Connector cover (tethered cap), for type-N connector
(25) N9912-20116 1 System board top shiel d ( 25)
(26) N9912-20028 1 Pad, A6 system board top shield to A2 LCD
(27) 8121-0964 1 Cable W3, RF coax with BNC connector, EXT TRIG/EXT REF connector
(28) 2190-0102 1 Washer, internal tooth, 15/32-inch
(29) 0590-1251 1 Nut, specialty, 15/32-inch - 32 thread
(30) 8121-1614 2 Cable W5 and W7, RF coa x, flexible
(31) 0515-0374 4 Screw, machine w/crest cup washer, pan head, M3.0 x 10 mm
(32) 0515-0430 6 Screw, machine w/crest cup washer, pan head, M3.0 x 6 mm
1. Each time the N9912A case is opened for a ny reason, you must order a Repair and Re-assembly Kit. See
“Miscellaneous Parts” on page 6-12.
6-8 Service Guide N9912-90003
RF Analyzer Replaceable Parts
N9912A Replaceable Parts Listings
Reference
Designator
(33) 0515-1940 4 Screw, machine w/patch lock , pan head, M2.5 x 6 mm
(34) 0515-2349 6 Screw, machine, 90-deg flat head, M3.0 x 14 mm
Part Number Qty Description
Figure 6-3 Measurement Group, Exploded View
Service Guide N9912-90003 6-9
Replaceable Parts RF Analyzer
Replaceable Parts Listings N9912A
Case Group
Reference
Designator
Replacement Assemblies
Front
Enclosure
Assembly
Rear
Enclosure
Assembly
I/O Panel
Assembly
Kick Stand
Assembly
1
Part Number Qty Description
N9912-60020 1
N9912-60022 1
N9912-60023 1
N9912-60028 1
Front Enclosure Assembly—Includes:
Front case with A1 keypad installed (1)
RFI O-strip, hollow (2)
LCD lens filter (3)
Keypad overlay (4)
Model label, nameplate overlay, 4 GHz (5)
Model label, nameplate overlay, 6 GHz (5)
Rear Enclosure Assembly—Includes:
Rear case (6)
RF gap pad (7)
Rear panel overlay (8)
I/O Panel Assembly—Includes:
System board connector panel (I/O side panel) (9)
Overlay, I/O pane l top (USB) (10)
Overlay, I/O panel middle (SD) (11)
Overlay, I/O panel botto m (LAN) (12)
Kick Stand Asse m bly—Includes:
Kickstand (13)
Friction hinge (14)
Screw (for hinge), qty 4 (15)
Hinge cover (16)
Screw (for hi nge cover), qty 4 (17)
Separately Replaceable Individual Parts and Assemblies
(14) 3110-0629 1 Friction hinge
(15) 0515-1940
(16) W1312-40068 1 Hinge cover
(17) 0515-5133
(18) 0515-5153
(19) N9 91 2-60 00 7 1 Battery cable
(20) W1312-40060
(21) N9912-40006
(22) 0515-1521
(23) N9910-80002
(24) W1312-40056
(25) 1480-0793
1. Each time the N9912A case is opened for any reason, you must order a Repair and Re-assembly Kit.
See “Miscellaneous Parts” on page 6-12.
4 Screw, machine w/patch lock, pan head, M2.5 x 6 mm
4 Screw, machine, button head, M3.0 x 8 mm
6 Screw, machine, w/flat washer, pan head, M3.0 x 35 mm
1 Battery door cover
2 Hole plugs
2 Screw, machine, 90-deg flat head, M3.0 x 5 mm
1 Strap handle
1 B lank side panel
4 Dowel pins
6-10 Service Guide N9912-90003
RF Analyzer Replaceable Parts
N9912A Replaceable Parts Listings
Reference
Designator
Part Number Qty Description
(26) W1312-60048
(27) W1312-60049
(28) W1312-60050
1 Door, top (USB)
1 Door, middle (SD)
1 Door, bottom (LAN)
Figure 6-4 Case Group, Exploded View
Service Guide N9912-90003 6-11
Replaceable Parts RF Analyzer
Replaceable Parts Listings N9912A
Miscellaneous Parts
Table 6-1 Part Numbers for Miscellaneous Parts and Accessories
Description
Repair and Re-assembly Kit
IMPORTANT
This kit is required each time the N9912A case is opened for any reason.
The kit includes the following items, some or all of which are necessary to re-assemble the internal assemblies
and the case, depending upon the depth of the repair.
Repair and Re-assembly Kit (Includes the following items.)
Gasket, for blank side panel (larger size); qty 1
Gasket, for I/O side panel (smaller size); qty 1
Screw, machine, w/flat washer, pan head, M3.0 x 35 mm; qty 6
Screw, machine, 90-deg flat head, M3.0 x 5 mm; qty 15
Screw, machine w/crest cup washer, pan head, M3.0 x 6 mm; qty 6
Screw, machine w/crest cup washer, pan head, M3.0 x 10 mm; qty 4
Screw, machine w/patch lock, pan head, M2.5 x 6 mm; qty 4
Screw, machine, 90-deg flat head, M3.0 x 14 mm; qty 6
Tape, 1/4-inch x 1-inch, for LCD ribbon cable; qty 3
Service Tools
T-8 TORX driver; set to 6 in-lb N/A
T-10 TORX driver; set to 9 in-lb N/A
5/16 inch, open-end torque wrench; set to 10 in-lb
7/16 inch, hex nut wrench or “nut driver”; set to 9 in-lb
9/16 inch, open-end torque wrench; set to 21 in-lb
Model or Part
Number
N9912-60027
N9912-40002
N9912-40003
0515-5153
0515-1521
0515-0430
0515-0374
0515-1940
0515-2349
N9912-20043
N/A
N/A
N/A
Documentation
Users’ Guide. Can also be printed from the Agilent Web site. Refer to “Printing Copies of
Documentation from the Web” on page iv.)
Quick Reference Guide N9912-90002
Service Guide. (Not available in printed form. Part number is for reference only. Must be
printed from the Agilent Web site. Refer to “Printing Copies of Documentation from the
Web” on page iv.)
ESD Supplies
Adjustable antistatic wrist strap 9300-1367
Antistatic wrist strap grounding cord (5 foot length) 9300-0980
Static control table mat and earth ground wire 9300-0797
ESD heel strap 9300-1126
Battery
Lithium-ion, 10.8 V, rechargeable (LCD gauge) 1420-0891
Lithium-ion, 10.8 V, rechargeable (LED gauge) 1420-0899
a. Refer to “Bat t ery Disposal” on page 1-7 for instructions on disposing of the old battery.
6-12 Service Guide N9912-90003
a
N9912-90001
N9912-90003
7 Repair and Replacement Procedures
Service Guide N9912-90003 7-1
Repair and Replacement Procedures RF Analyzer
Information in This Ch apter N9912A
Information in This Chapter
This chapter contains procedures for removing and replacing the major assemblies of your
Agilent Technologies PNA series microwave network analyzer.
Chapter Seven at-a-Glance
Section Title Summary of Content Start Page
Personal Safety Warnings Warnings and cautions pertaining to personal
safety.
Electrostatic Discharge (ESD)
Protection
Assembly Replacement
Sequence
Table of Removal and
Replacement Procedures
Removal and Replacement
Procedures
Post-Repair Procedures A table of the proper tests, verifications, and
Information pertaining to ESD protection. Page 7-3
A step-by-step procedure for how to identify
the faulty assembly, replace it with a new one,
and re-adjust your analyzer when done.
A table of removal and replacement
procedures and the corresponding page
number where they are located.
The actual procedures for removing and
replacing the major assemblies in your
analyzer.
The procedures occur in assembly reference
designator numerical order.
adjustments to perform on your analyzer after
repair.
Page 7-3
Page 7-4
Page 7-4
See Table 7-1
on page 7-4
for specific
procedures.
Page 7-39
7-2 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Personal Safety Warnings
Personal Safety Warnings
WARNING These servicing instructions are for use by qualified personnel only.
To avoid electrical shock, do not perform any servicing unless you
are qualified to do so.
WARNING Danger of explosion if battery is incorrectly replaced. Replace only
with the same or equivalent type recommended. Discard used
batteries according to manufacturer’s instructions.
Safety Earth Ground
WARNING This is a Safety Class I product (provided with a protective earthing
ground incorporated in the power cord). The mains plug shall only
be inserted in a socket outlet provided with a protective earth
contact. Any interruption of the protective conductor, inside or
outside of the instrument, will make the instrument dangerous.
Intentional interruption is prohibited.
CAUTION Always use the three-prong AC power cord supplied with this product.
Failure to ensure adequate grounding by not using this cord may cause
product damage.
Electrostatic Discharge (ESD) Protection
CAUTION Many of the assemblies in this instrument are very susceptible to damage
from electrostatic discharge (ESD). Perform the following procedures only at
a static-safe workstation and wear a grounded wrist strap.
This is important. If not properly protected against, electrostatic discharge
can seriously damage your analyzer, resulting in costly repair.
To reduce the chance of electrostatic discharge, follow all of the
recommendations outlined in “Electrostatic Discharge Protection” on
page 1-5, for all of the procedures in this chapter.
Service Guide N9912-90003 7-3
Repair and Replacement Procedures RF Analyzer
As s e m bly R e p l a c emen t Sequen c e N9912A
Assembly Replacement Sequence
The following steps show the sequence that you should follow to replace an assembly in the
network analyzer.
Step 1. Identify the faulty group. Begin with Chapter 4, “Troubleshooting.”
Step 2. Order a replacement assembly. Refer to Chapter 6, “Replaceable Parts.”
Step 3. Replace the faulty assembly and determine what adjustments are necessary.
Refer to “Post-Repair Procedures” in this chapter.
Step 4. Perform the necessary adjustments. Refer to Chapter 3, “Tests and Adjustments.”
Step 5. Perform the necessary performance tests. Refer to Chapter 3, “Tests and
Adjustments.”
Removal and Replacement Procedures
Table 7-1 List of Procedures
Reference
Designator
or Name
Case parts All enclosure case parts Page 7-6
RPG RPG (part of front panel group) Page 7-18
RPG knob RPG knob (part of front panel group) Page 7-18
RTC
battery
Main battery Primary power battery Page 7-5
A1 Keypad Page 7-22
A2 LCD Page 7-20
A3 Front panel interface board Page 7-22
A4 RF board Page 7-25
Assembly Description Location
Backup battery for real time clock (Soldered onto the A3 front panel
interface board.)
Page 7-24
A5 System board Page 7-25
A6
7-4 Service Guide N9912-90003
SOM board Page 7-25
RF Analyzer Repair and Replacement Procedures
N9912A Re moving and R eplacin g the Mai n Batter y
Removing and Replacing the Main Battery
Tools Required
•None
IMPORTANT Refer to “Battery Disposal” on page 1-7 for important instructions on
disposing of the old battery.
Replacing the Main Battery
1. Disconnect the power cord.
2. Remove the battery compartment door by pushing in on the detent and then sliding the
door downwards.
3. Note the orientation of the battery for installation of the replacement.
4. Remove the old battery and install the new battery in the battery compartment.
5. Reinstall the battery compartment door by aligning it in position and then sliding it
upwards until an audible click is heard.
Figure 7-1 Replacing the Main Battery
Service Guide N9912-90003 7-5
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
Removing and Replacing the Case Group Parts
Tools Required
• T-8 TORX driver (set to 6 in-lb)
• T-10 TORX driver (set to 9 in-lb)
•Isopropyl alcohol (Use only in a well ventilated area.)
• Repair and Re-assembly Kit. Re fer to “Miscellaneous Parts” on page 6-12.
WARNING Before beginning any repair, disconnect the power cord.
Replacing the Kickstand, Hinge Cover, and Hinge
1. Remove, and discard, the four screws (item 1) from the kickstand hinge cover. New
screws are provided in the Repair and Re-assembly Kit.
Figure 7-2 Replacing the Kickstand and Hinge Cover
7-6 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
2. To replace the entire kickstand assembly:
a. Lift the kickstand assembly off of the rear case and discard it.
b. Place the new kickstand assembly on the rear case.
c. Place the new hinge cover in position and secure it with four new screws. A new
hinge cover and new screws are provided in the Repair and Re-assembly Kit.
3. To replace the hinge cover:
a. Position the new hinge cover in place and install four new screws. New screws are
provided in the Repair and Re-assembly Kit.
4. To replace the hinge:
a. Lift the kickstand assembly off of the rear case.
b. Remove and discard the four hinge attachment screws (item 2).
c. Place the new hinge in position and install with four new screws. New screws are
provided in the Repair and Re-assembly Kit.
d. Place the kickstand assembly in place on the rear case and reinstall the hinge cover
with new screws provided in the Repair and Re-assembly Kit.
Figure 7-3 Replacing the Hinge
Service Guide N9912-90003 7-7
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
Separating the Front and Rear Cases
1. Remove the battery. Refer to “Removing and Replacing the Main Battery” on page 7-5.
2. Loosen the six screws (item 3) that secure the RF top panel. It should not be necessary
to remove these screws, just loosen them.
3. Remove, and discard, the six screws (item 4) that secure the rear case to the front case.
New screws are provided in the Repair and Re-assembly Kit.
Figure 7-4 Separating the Front and Rear Cases (1)
7-8 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
4. Separate the cases and position the rear case to one side, as shown in Figure 7-5, to
allow access to the blank side panel and strap handle.
5. Remove the strap handle from the two dowel pins.
6. Remove the blank side panel from the groove in the front case.
Figure 7-5 Separating the Front and Rear Cases (2)
Service Guide N9912-90003 7-9
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
7. Position the cases side-by-side as shown in Figure 7-6.
8. Unplug the battery cable, W10, from the A5 system board at the location indicated.
9. The front and rear cases are now completely separated.
10. Remove the blank side panel by lifting it from the groove in the front case.
NOTE If the FieldFox serial number is below xx4910xxxx, temporarily remove the
LCD shield and verify that two strips of adhesive tape are in place as shown
in Figure 7-15 on page 7-21. To remove the LCD shield, follow Step 2a on
page 7-20. If the two strips of adhesive tape are not in place, install them by
following Step 2h on page 7-20.
Figure 7-6 Separating the Front and Rear Cases (3)
7-10 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
Replacing the Battery Cable
1. Separate the front and rear cases. See “Separating the Front and Rear Cases” on
page 7-8.
2. Note the orientation of the cable for installation of the new cable, then, using a small
flat-blade screwdriver to move the cable connector, release the retention clips on the
cable connector and remove the cable from the rear case.
Figure 7-7 Replacing the Battery Cable
3. When installing the new battery cable, make sure that the connector snaps into place.
4. Reinstall the rear case onto the front case. See Combining the Front and Rear Cases.
Replacing the Rear Case
1. Separate the front and rear cases. See Separating the Front and Rear Cases.
2. Carefully remove the serial number label and the Windows CE label from the back of
the old rear case and apply the labels to the new rear case.
3. Remove the kickstand assembly from the old rear case and install it on the new rear
case. See Replacing the Kickstand, Hinge Cover, and Hinge.
4. Remove the battery cable from the old case and install it in the new case. See Replacing
the Battery Cable.
5. Install the new rear case onto the front case. See Combining the Front and Rear Cases.
Replacing the Strap Handle
1. Separate the front and rear cases to the positions shown in Figure 7-5. See Separating
the Front and Rear Cases.
2. Note the orientation of the strap handle, then lift it off of the dowel pins at each end.
3. Slip the new strap handle over the dowel pins.
Service Guide N9912-90003 7-11
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
4. Reinstall the rear case onto the front case. See Combining the Front and Rear Cases.
Replacing the I/O Side Panel, Doors, and Gasket
1. Separate the front and rear cases. See “Separating the Front and Rear Cases” on
page 7-8.
2. Remove the measurement group assemblies (RF top panel assembly, A4 RF board, A5
system board, and A6 SOM board) as one unit with the I/O panel attached, but do not
disconnect cable W11 from between the A2 LCD and the A5 system board. Refer to
“Removing and Replacing the Measurement Group Assemblies” on page 7-25.
3. Remove the two screws (item 5) that secure the I/O side panel to the A5 system board
and remove the I/O side panel.
Figure 7-8 Replacing the I/O Side Panel
7-12 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
4. Remove the three doors from the old I/O side panel:
a. Open each door to its stopping point, then GENTLY force it beyond its stopping point
to separate it from the panel.
5. Install the three doors in the new I/O side panel:
a. Place each door in its respective opening with the hinges aligned with the hinge slots
in the side panel.
b. Press the hinges into their slots until they snap into place.
Figure 7-9 Replacing the I/O Side Panel Doors and Gasket
6. Before installing the new I/O side panel, or when reinstalling the existing I/O side
panel, install a new gasket in the groove around the perimeter of the panel.
If an old gasket must be removed, use tweezers being careful not to damage the groove.
Start in the groove near the flat end of the side panel. Be careful not to stretch or
damage the gasket in any way. Also, make sure there is no slack in the gasket. A new
gasket is provided in the Repair and Re-assembly Kit (see page 6-12). It is the smaller
of the two gaskets provided in the kit.
7. To install the new I/O side panel, place it in position on the A5 system board and
reinstall the two attachment screws. See Figure 7-8.
8. Reinstall the measurement group assemblies (RF top panel assembly, A4 RF board, A5
system board, and A6 SOM board) as one unit with the new I/O panel attached.
9. Reinstall the rear case onto the front case. See Combining the Front and Rear Cases.
Service Guide N9912-90003 7-13
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
Replacing the Front Case (including the A1 Keypad)
1. Separate the front and rear cases. See Separating the Front and Rear Cases.
2. Remove the measurement group assemblies (RF top panel assembly, A4 RF board, A5
system board, and A6 SOM board) as one unit with the I/O panel attached. Refer to
“Removing and Replacing the Measurement Group Assemblies” on page 7-25.
3. Remove the front panel group assemblies (A2 LCD, A3 front panel interface board, and
RPG). Refer to “Removing and Replacing the Front Panel Group Assemblies” on
page 7-18.
Figure 7-10 Replacing the Front Case
4. Carefully remove the serial number label from the inside bottom of the old front case
and apply the label to the new front case.
5. Choose the appropriate model number nameplate overlay for your analyzer, remove the
protective backing to expose the adhesive, and adhere it in the location shown.
6. Remove the dowel pins (item 5) from the old front case and install them in the new case.
The other two dowel pins should already be installed in the case.
7. Make sure that the gaskets (item 6) are all in place in the grooves, that there are no
gaps, and that they are not damaged in any way.
8. Refer to “Removing and Replacing the Front Panel Group Assemblies” on page 7-18 to
reinstall the front panel group assemblies removed in step 3.
9. Refer to “Removing and Replacing the Measurement Group Assemblies” on page 7-25 to
reinstall the measurement group assemblies removed in step 2.
7-14 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
10.Reinstall the rear case onto the front case. Refer to “Combining the Front and Rear
Cases” on page 7-15.
Combining the Front and Rear Cases
1. Install a new gasket on the blank side panel being careful not to stretch it or to damage
it in any way. Also, make sure there is no slack in the gasket. A new gasket is provided
in the Repair and Re-assembly Kit (the blank side panel uses the larger of the two
gaskets provided). If an old gasket must be removed, carefully remove it with tweezers
being careful not to damage the groove.
2. If a new gasket has not been installed on the I/O side panel, install it at this time. It will
be necessary to remove the I/O side panel from the A5 system board. Refer to “Replacing
the I/O Side Panel, Doors, and Gasket” on page 7-12 for instructions.
3. Position the front and rear cases side-by-side as shown.
4. Plug the battery cable, W10, into the A5 system board as indicated.
Figure 7-11 Combining the Front and Rear Cases (1)
Service Guide N9912-90003 7-15
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the C a se G r o u p Part s N9912A
5. Position the rear case on top of the front case and to one side as shown.
6. Place the blank side panel in the groove in the front case being careful not to damage
the gasket.
7. Position the strap handle over the two dowel pins as shown.
Figure 7-12 Combining the Front and Rear Cases (2)
7-16 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re mov ing a nd Repla cing the Cas e Gr o up Parts
8. Position the rear case directly over, and aligned with, the front case and the side panels
as shown.
9. Make sure the battery cable is tucked in between the measurement group assemblies
and the blank side panel and that it is not in the path of the screw hole indicated.
10. Firmly press the cases together being careful not to damage the gaskets.
11. Install six new screws (item 7) to secure the rear case to the front case. These new
screws are provided in the Repair and Re-assembly Kit.
12. Tighten the six screws (item 8) that secure the RF top panel.
Figure 7-13 Combining the Front and Rear Cases (3)
13. Reinstall the battery. Refer to “Removing and Replacing the Main Battery” on page 7-5.
Service Guide N9912-90003 7-17
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the Front P a nel Group Assembli es N9912A
Removing and Replacing the Front Panel Group Assemblies
Tools Required
• T-8 TORX driver (set to 6 in-lb)
• T-10 TORX driver (set to 9 in-lb)
• 7/16-inch hex nut wrench or “nut driver” (set to 9 in-lb)
• Repair and Re-assembly Kit. Re fer to “Miscellaneous Parts” on page 6-12.
• Soldering tool (Required only for RTC battery replacement.)
WARNING Before beginning any repair, disconnect the power cord.
Pre-replacement Procedure
1. Separate the front and rear cases. Refer to “Separating the Front and Rear Cases” on
page 7-8.
2. Remove the measurement group assemblies (RF top panel, A4 RF board, A5 system
board, and A6 SOM board) as one unit with the I/O panel attached. Refer to “Removing
and Replacing the Measurement Group Assemblies” on page 7-25.
Replacing the RPG and RPG Knob
1. Perform the steps under “Pre-replacement Procedure” on page 7-18.
2. Remove the two hole plugs from the back side of the front case, next to the RPG.
3. To replace the RPG knob:
a. Insert a round shaft, such as a screwdriver shaft, into the exposed holes and push
the RPG knob off of the RPG shaft to the front side of the front case.
b. Install a new knob by aligning the D-shaped detent in the knob with the D-shape on
the shaft and push the knob into position.
4. To replace the RPG:
a. Remove the RPG knob. Refer to step 3.a of this procedure.
b. Disconnect the RPG cable, W12, from the A3 front panel interface board.
c. Using a 7/16-inch hex nut wrench, remove the hex nut from the RPG shaft.
d. Pull the RPG out the back side of the front case and retrieve the lock washer from
the front side.
e. To install a new RPG, reverse the above steps. A new cable, nut, and washer are
included with the new RPG. When reinstalling the RPG cable, W12, bend the cable
toward the right side on top of the display to front panel interface board cable.
5. Reinstall the hole plugs in the front case. Apply one drop of isopropyl alcohol on each
hole plug to lubricate it, making it easier to install. Use alcohol only in a well
7-18 Service Guide N9912-90003
RF Analyzer Repair and Replacement Procedures
N9912A Re moving and Replaci ng the Front Pa nel Gro u p Assemblie s
ventilated area. View the hole plugs from the front to ensure that they are fully
seated. These hole plugs must be installed to maintain water-tight integrity.
6. Reinstall the RPG knob. Refer to step 3.b of this procedure.
7. Perform the steps under “Post-replacement Procedure” on page 7-24.
Figure 7-14 Replacing the RPG and RPG Knob
Service Guide N9912-90003 7-19
Repair and Replacement Procedures RF Analyzer
Re m ovin g and Re placing the Front P a nel Group Assembli es N9912A
Replacing the A2 LCD, the LCD Shield, and LCD Cables
1. Perform the steps under “Pre-replacement Procedure” on page 7-18.
2. To replace the LCD shield:
a. Remove the four screws (item 1) that attach the LCD shield and discard them. New
screws are provided in the Repair and Re-assembly Kit.
b. Lift the LCD shield off of the A2 LCD.
c. Install new gap pads on the new LCD shield in the locations shown. Refer to Figure
7-15 and Figure 7-8 on page 7-12 for placement of gap pads.
d. Place the new LCD shield in position on the A2 LCD and secure it with four new
screws (item 1). These screws are provided in the Repair and Re-assembly Kit.
3. To replace the LCD cables and the A2 LCD:
a. Remove the LCD shield. Refer to steps 2.a and 2.b of this procedure.
b. Disconnect the A2 LCD to A3 FPIB cable, W13, at the A2 LCD. If replacing only this
cable:
1. Disconnect the cable at both ends.
2. Remove the cable from beneath the RPG cable, W12.
3. Route the new cable beneath the RPG cable as shown and re-connect both ends.
4. Bend the RPG cable toward the right side as shown.
5. Skip to step 3.h.
c. Note the location of the adhesive tape over the connector on the A2 LCD to
A5 system board cable, W11. Remove the tape and disconnect the cable. If replacing
only this cable:
1. Connect the new cable.
2. Skip to step 3.h.
d. Remove the A2 LCD from the front case.
e. Place the new A2 LCD in position and re-connect the cables.
f. Place a strip of adhesive tape over the LCD connector end of the A2 LCD to
A5 system board cable W11, in the same location as the old strip and as shown. A
new strip of adhesive tape is provided in the Repair and Re-assembly Kit.
g. Connect cable W13 to the A2 LCD.
h. There are two identical connectors, CN3 and CN4, near the connector for cable W13.
A strip of adhesive tape should cover each connector as shown in Figure 7-15. If not,
apply tape strips by cutting a strip of adhesive tape (provided) in half and applying
one half to each connector as shown in Figure 7-15. Press down firmly on the tape to
conform it to the contours of the connectors and to ensure proper adhesion. The strip
of adhesive tape is part of the N9912-60027 Repair and Re-assembly Kit.
i. Reinstall the LCD shield with four new screws provided in the Repair and
Re-assembly Kit. Refer to step Step d on page 7-20 of this procedure.
7-20 Service Guide N9912-90003
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