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  5-1

Keysight RF Vector Network Analyzer
FieldFox

Service Guide

5

Theory of Operation

Information in This Chapter

This chapter provides a general description of the operating theory of the 

N9923A 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.

page  5-2

Front Panel Group

Operation of the assemblies associated with the front panel 

group of assemblies.

page  5-4

Measurement Group

Operation of the assemblies associated with the 

measurement group of assemblies.

page  5-6

Operation in Modes

Description of the different operating modes and what 

hardware is used in each mode.

page  5-18

Temperature Related 

Information

Information about temperature sensors and how the 

analyzer responds to temperature information gathered.

page  5-20

User Calibration in CAT and NA 

Modes

Descriptions of one port and two port calibrations for the 

CAT and NA modes of operation.

page  5-21

Firmware Related Information

Information about firmware and firmware upgrades.

page  5-23

Summary of Contents for N9923A

Page 1: ...Service Guide Keysight N9923A FieldFox RF Vector Network Analyzer 2 MHz 4 GHz 2 MHz 6 GHz ...

Page 2: ...S government customers under its standard commercial license which is embodied in its End User License Agreement EULA a copy of which can be found at http www keysight com find sweula The license set forth in the EULA represents the exclusive authority by which the U S government may use modify distribute or disclose the Software The EULA and the license set forth therein does not require or permi...

Page 3: ...http www keysight com find cxa http www keysight com find mxe To receive the latest updates by email subscribe to Keysight Email Updates at the following URL http www keysight com find MyKeysight Information on preventing instrument damage can be found at www keysight com find PreventingInstrumentRepair Is your product software up to date Periodically Keysight releases software updates to fix know...

Page 4: ... 1 Maintenance 2 2 Physical Maintenance 2 2 Electrical Maintenance 2 2 Analyzer Options 2 3 Frequency Range Options 2 3 Network Analyzer NA Options 2 3 Power Meter PM Option 2 3 Cable and Antenna Test CAT Option 2 3 Vector Voltmeter VVM Option 2 4 Keysight Support Services and Assistance 2 5 Service and Support Options 2 5 Calibration Options 2 5 Contacting Keysight 2 6 Shipping Your Analyzer to K...

Page 5: ...tatic Discharge ESD 4 2 Assembly Replacement Sequence 4 3 Getting Started with Troubleshooting 4 4 Check the Basics 4 4 Troubleshooting Organization 4 4 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 1 Chapter Five at a Glance 5 1 Analyzer System Operation 5 2 Functional Groups of the Anal...

Page 6: ...5 24 LAN Interface 5 25 6 Replaceable Parts Information in This Chapter 6 1 Chapter Six at a Glance 6 1 Ordering Information 6 2 Assembly Replacement Procedure 6 3 Replaceable Parts Listings 6 4 Entire Analyzer 6 4 Front Panel Group 6 5 Measurement Group 6 7 Case Group 6 10 Miscellaneous Parts 6 12 7 Repair and Replacement Procedures Information in This Chapter 7 1 Chapter Seven at a Glance 7 1 Pe...

Page 7: ... 8 1 Chapter Eight at a Glance 8 1 Supplemental Information 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 7 To Check the Current Firmwa...

Page 8: ...e Section Title Summary of Content Start Page Safety Symbols Descriptions of CAUTION and WARNING symbols used throughout this manual page 1 2 General Safety Considerations A list of safety points to consider when servicing your network analyzer page 1 3 Electrostatic Discharge Protection A discussion of electrostatic discharge ESD and related recommendations and requirements for ESD protection pag...

Page 9: ...rd 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 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 b...

Page 10: ...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 This product is designed for use in Installation Category II and Pollution Degree 2 per IEC 61010 1 The measuring terminals on this instrument are designed to be used with external signals described in Measurem...

Page 11: ...t remove covers For continued protection against fire hazard replace line fuse only with same type and rating The use of other fuses or material is prohibited 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 disconnect...

Page 12: ...ons 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 t...

Page 13: ...1 6 Keysight N9923A Service Guide Safety and Regulatory Information Electrostatic Discharge Protection 1 Figure 1 1 ESD Protection Setup ...

Page 14: ...The CSA mark is a registered trademark of the CSA International This mark designates the product is an Industrial Scientific and Medical Group 1 Class A product reference CISPR 11 Clause 5 This is a marking to indicate product compliance with the Canadian Interference Causing Equipment Standard ICES 001 IP 2 0 The instrument has been designed to meet the requirements of IP 2 0 for egress and opera...

Page 15: ...f it in accordance with your country s requirements If required you may return the battery to Keysight Technologies for disposal Refer to Contacting Keysight on page 2 6 for assistance For instructions on removing and replacing the primary power battery refer to Removing and Replacing the Main Battery on page 7 6 For instructions on removing and replacing the RTC real time clock battery located on...

Page 16: ...l surfaces of your analyzer Information about electrical maintenance of your analyzer page 2 2 Analyzer Options A list of the options available for the microwave network analyzers page 2 3 Keysight Support Services and Assistance The Internet address URL for Keysight assistance Service and support options available Calibration options available Important information about shipping your analyzer to...

Page 17: ...ry or slightly damp cloth only Electrical Maintenance Refer to Contacting Keysight on page 2 6 and to Chapter 3 Tests and Adjustments 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 ...

Page 18: ... Network Analyzer NA Options Option 122 Full 2 Port S Parameters The standard vector network analyzer allows you to make S11 and S21 measurements Option 122 allows you to make S11 S12 S21 S22 A B R1 and R2 measurements Option 112 QuickCal This option provides a calibration that is performed automatically using calibration standards that are built in to the N9923A Calibration standards are automati...

Page 19: ...Fault DTF DTF and Return Loss Return Loss dB VSWR DTF VSWR Cable Loss 1 port Insertion Loss 2 port Vector Voltmeter VVM Option Option 308 Vector Voltmeter Mode This option allows you to make the following measurements 1 port cable trimming magnitude and phase 2 port transmission magnitude only ...

Page 20: ...st 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 calibra...

Page 21: ...r network analyzer to Keysight 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 Keysight for instructions on where to ship your analyzer Refer to Contacting Keysight on page 2 6 Printing Copi...

Page 22: ...Keysight N9923A Service Guide 2 7 General Product Information Keysight Support Services and Assistance Enter the document s part number located on the title page in the Search box Click Search ...

Page 23: ...2 8 Keysight N9923A Service Guide General Product Information Keysight Support Services and Assistance 2 ...

Page 24: ...art Page Before You Begin Items to consider or procedures to perform before testing is begun Verify the operating environment Protect Against Electrostatic Discharge ESD Allow the Analyzer to Warm Up Review the Principles of Connector Care page 3 2 Service Test Equipment A list of additional equipment recommended for servicing the N9923A analyzer page 3 4 Before Returning an Instrument to a Custom...

Page 25: ...nd 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 con...

Page 26: ... block Gage all connectors before first use Making Connections Do Align connectors carefully Do Not Apply bending force to connection Make preliminary connection contact lightly Over tighten preliminary connection Turn only the connector nut Twist or screw any connection Use a torque wrench for final connection Tighten past torque wrench break point a Cleaning connectors with alcohol shall only be...

Page 27: ...B memory stick Must be 128 MB or larger Small free standing fan Used to cool the analyzer if internal temperature is too high See UUT 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 Micro SD flash card Required to r...

Page 28: ...ing 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 N9923A is operating and confirm that the power cord icon is displayed appropriately at the top of the display Charge the battery to 80 o...

Page 29: ...PORT 1 and Port 2 connectors open 3 Press Scale Amptd Ref Pos 2 Enter 4 Press Scale 1 Enter 5 The trace should be between 1 and 1 dB S11 is displayed 6 Press Measure 7 If the S22 soft key exists press it to display S22 a The trace should be between 1 and 1 dB If the operational check fails allow the instrument to warm up for 15 minutes and try again ...

Page 30: ...T Error Terms This test checks the quality of the CalReady calibration It measures a short connected to the port under test Note The Error Terms adjustment should be performed every twelve months to preserve calibration accuracy for CalReady System Dynamic Range This test performs a two port isolation calibration which sets the reference power to the power output level of each port 0 dB the power ...

Page 31: ... process creates factors for various phase lock capture speeds used during measurements No test equipment is required Error Terms This adjustment process updates the correction information used by CalReady i e the Factory Cal It uses an ECal to perform a one port cal on each port then completes a two port cal using the thru and loads Note The Error Terms adjustment should be performed every twelve...

Page 32: ...ons Note that the N7800A software must be installed prior to installing the N7841A and it requires a separate license The web page for the N7841A download also provides a link to the N7841A help This help system provides user instructions and lists of required equipment It may be accessed prior to downloading the software Keysight FieldFox Customer Support Web Pages The following URL provides upda...

Page 33: ...3 10 Keysight N9923A Service Guide Tests and Adjustments Test Software and Information Available on the Web 3 ...

Page 34: ...ubleshooting 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 A starting point to begin troubleshooting page 4 4 Power Up Troubleshooting Power up problems Power supply problems page 4 6 Front Panel Group Troubleshooting Problems with the fro...

Page 35: ...charge ESD 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 ...

Page 36: ...hese 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 ...

Page 37: ...mmended 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...

Page 38: ... Guide 4 5 Troubleshooting Getting Started with Troubleshooting Figure 4 1 Troubleshooting Organization Flowchart Go to Front Panel Group Troubleshooting Go to Measurement Group Troubleshooting Go to Power Up Troubleshooting ...

Page 39: ...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 success...

Page 40: ...y 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 ...

Page 41: ...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 ...

Page 42: ... of the major functional groups of the analyzer page 5 2 Front Panel Group Operation of the assemblies associated with the front panel group of assemblies page 5 4 Measurement Group Operation of the assemblies associated with the measurement group of assemblies page 5 6 Operation in Modes Description of the different operating modes and what hardware is used in each mode page 5 18 Temperature Rela...

Page 43: ...e 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 affe...

Page 44: ...Keysight N9923A Service Guide 5 3 Theory of Operation Analyzer System Operation Figure 5 1 Overall Block Diagram ...

Page 45: ...d 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 th...

Page 46: ...d 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 co...

Page 47: ... LO output is delivered to the NA mixers of both ports The LO frequency is always above the measured frequency The IF is 390 kHz The 30 MHz time base is also used to generate a source signal in the source synthesizer that covers the frequency range of 2 MHz to 6 GHz The source signal is generally rich in harmonic content This is acceptable because the signal is used with tuned receivers The freque...

Page 48: ...Keysight N9923A Service Guide 5 7 Theory of Operation Measurement Group 10 49 607 50 000 21 5099 705 6000 000 11 50 000 99 607 a Except for band 1 start frequency is previous stop frequency 0 001 Hz ...

Page 49: ...5 8 Keysight N9923A Service Guide Theory of Operation Measurement Group 5 Figure 5 2 Simplified RF Block Diagram ...

Page 50: ... 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 Reflectometer put into a low power state The load switching for the Source and LO sections is accomplished on the A5 system board via the Analog Power Supply Load Switc...

Page 51: ...d 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 sensor and...

Page 52: ...tages 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 conserve power and minimize heat This is accomplished through load switching See Power Management Circuitry on page 5 8 for more information ...

Page 53: ...e Guide Theory of Operation Measurement Group 5 Figure 5 3 Simplified System Board Block Diagram The System Monitor controls the on off functions of the analog power supplies All are on or off together except for power sequencing ...

Page 54: ...cy Reference section of the N9923A FieldFox RF Vector Network Analyzer User s Guide Part Number N9923 90001 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...

Page 55: ... real time clock 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...

Page 56: ... 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 boar...

Page 57: ...s 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 ...

Page 58: ...onitor 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 l...

Page 59: ...t is displayed in the battery icon 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 ...

Page 60: ...ration 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 Service Related User Opera...

Page 61: ...ements listed below but are separate operating modes 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 There is no user control of the power level directly out of the source synthesizer on the A4 RF board The only user control of output power level is the high low setting 45 dB in or out Mea...

Page 62: ...in the case of extreme temperatures See Chapter 8 for instructions on viewing temperature readings See the N9923A FieldFox RF Vector Network Analyzer User s Guide Part Number N9923 90001 FieldFox High Temperature Protection section for information about operation at high temperature The internal temperature of the unit is critical when executing the TME based software for tests and adjustments See...

Page 63: ... Factory Calibration When the analyzer is adjusted at the factory or during annual calibration a preset calibration is stored in the analyzer CalReady The preset calibration covers the full frequency range of the analyzer The preset calibration is active whenever CalRdy is displayed on the left side of the screen Presetting the analyzer activates the preset calibration The preset calibration provi...

Page 64: ...on 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 User Calibration A user calibration is performed with a mechanical cal kit The N9923A User s Guide Part Number N9923 90001 refers to a user calibration as a mechanical cal ...

Page 65: ...re 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...

Page 66: ...Refer to instructions in the Update FieldFox Firmware section of the N9923A FieldFox RF Vector Network Analyzer User s Guide Part Number N9923 90001 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...

Page 67: ...01 for details on reviewing and configuring LAN settings 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 ove...

Page 68: ...r 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 How to order a replaceable part from Keysight Technologies page 6 2 Assembly Replacement Procedure The correct sequence for determining the failure of and replacing a defective assembly page 6 3 Replaceable Parts L...

Page 69: ...nologies for instructions on where to send the order Refer to Contacting Keysight on page 2 6 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 Keysight Technologies for instructions on where to send the order Refer to Con...

Page 70: ...e 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 S...

Page 71: ...d 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 5 Measurement Group on page 6 7 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 ...

Page 72: ...Assembly and not separately replaceable see Case Group on page 6 10 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 RPG knob 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 sy...

Page 73: ...6 6 Keysight N9923A Service Guide Replaceable Parts Replaceable Parts Listings 6 Figure 6 2 Front Panel Group Exploded View ...

Page 74: ... 2 gaskets 21 Clamp stick on qty 2 Coax Cable Assembly N9912 60029 1 Coax Cable Assembly Includes the following 22 Cables W4 and W6 RF flexible qty 2 23 Spiral wrap plastic RF Top Panel Assembly N9923 60021 1 RF Top Panel Assembly Includes the following 24 Panel RF die cast 25 Connector cover tethered cap for type N connector qty 2 26 Overlay RF 27 Gasket RF 30 Cable W3 RF coax with BNC connector ...

Page 75: ...her internal tooth 15 32 inch 32 0590 1251 1 Nut specialty 15 32 inch 32 thread 33 8121 1929 2 Cable W5 and W7 RF coax flexible 34 0515 0374 4 Screw machine w crest cup washer pan head M3 0 x 10 mm 35 0515 0430 6 Screw machine w crest cup washer pan head M3 0 x 6 mm 36 0515 1940 4 Screw machine w patch lock pan head M2 5 x 6 mm 37 0515 2349 6 Screw machine 90 deg flat head M3 0 x 14 mm Reference D...

Page 76: ...Keysight N9923A Service Guide 6 9 Replaceable Parts Replaceable Parts Listings Figure 6 3 Measurement Group Exploded View ...

Page 77: ...O panel top USB 11 Overlay I O panel middle SD 12 Overlay I O panel bottom LAN Kick Stand Assembly N9912 60028 1 Kick Stand Assembly Includes the following 13 Kickstand 14 Friction hinge 15 Screw for hinge qty 4 16 Hinge cover 17 Screw for hinge cover qty 4 29 Spacer for hinge qty 2 Separately Replaceable Individual Parts and Assemblies 4 N9912 80005 1 Keypad overlay 5 N9923 80001 1 Model label na...

Page 78: ...rew machine 90 deg flat head M3 0 x 5 mm 23 N9910 80002 1 Strap handle 24 W1312 40056 1 Blank side panel 25 1480 0793 4 Dowel pins 26 W1312 60048 1 Door top USB 27 W1312 60049 1 Door middle SD 28 W1312 60050 1 Door bottom LAN 29 N9912 00003 2 Hinge spacer see Figure 6 5 One spacer located between 14 and 6 and another spacer located between 16 and 6 Reference Designator Part Number Qty Description ...

Page 79: ...pon 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 ...

Page 80: ...r s Guide N9923 90001 Programming Guide N9923 90003 Service Guide N9923 90018 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 Batterya Lithium ion 11 1 V rechargeable LCD gauge 1420 0908 a Refer to Battery Disposal on page 1 8 for instructions on ...

Page 81: ...6 14 Keysight N9923A Service Guide Replaceable Parts Replaceable Parts Listings 6 ...

Page 82: ...Assembly Replacement Sequence 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 page 7 4 Table of Removal and Replacement Procedures A table of removal and replacement procedures and the corresponding page number where they are located page 7 5 Removal and Replacement Procedures The actual procedures for removing and re...

Page 83: ... type recommended Discard used batteries according to manufacturer s instructions 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 dangero...

Page 84: ...ic 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 a...

Page 85: ...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 ...

Page 86: ...rts All enclosure case parts page 7 7 RPG RPG part of front panel group page 7 21 RPG knob RPG knob part of front panel group page 7 21 RTC battery Backup battery for real time clock Soldered onto the A3 front panel interface board page 7 26 Main battery Primary power battery page 7 6 A1 Keypad page 7 24 A2 LCD page 7 22 A3 Front panel interface board page 7 24 A4 RF board page 7 28 A5 System boar...

Page 87: ...ng 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 Refer to Battery Disposa...

Page 88: ...set to 9 in lb Isopropyl alcohol Use only in a well ventilated area Repair and Re assembly Kit Refer to Miscellaneous Parts on page 6 12 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 Before beginning any repair disco...

Page 89: ...d 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 scr...

Page 90: ...nd Rear Cases 1 Remove the battery Refer to Removing and Replacing the Main Battery on page 7 6 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 ...

Page 91: ...arts 7 Figure 7 4 Separating the Front and Rear Cases 1 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 ...

Page 92: ...re 7 5 Separating the Front and Rear Cases 2 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 ...

Page 93: ...ry Cable 1 Separate the front and rear cases See Separating the Front and Rear Cases on page 7 9 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 Do not over bend the retention clips as they could break ...

Page 94: ...ply 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...

Page 95: ...t cable W11 from between the A2 LCD and the A5 system board Refer to Removing and Replacing the Measurement Group Assemblies on page 7 28 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 4 Remove the three doors from the old I O side panel a Open each door to its stopping point then GENTLY for...

Page 96: ... 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 g...

Page 97: ...e 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 ot...

Page 98: ... 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 ...

Page 99: ...e Group Parts 7 Figure 7 11 Combining the Front and Rear Cases 1 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 ...

Page 100: ... 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 Tight...

Page 101: ...vice Guide Repair and Replacement Procedures Removing and Replacing the Case Group Parts 7 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 6 ...

Page 102: ...nd Replacing the Measurement Group Assemblies on page 7 28 Replacing the RPG and RPG Knob 1 Perform the steps under Pre replacement Procedure on page 7 21 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 ...

Page 103: ...easier to install Use alcohol only in a well 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 27 Figure 7 14 Replacing the RPG and RPG Knob Replacing the A2 LCD the LCD...

Page 104: ...he 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 Pl...

Page 105: ...crews new ones are provided in the Repair and Re assembly Kit Be careful The A2 LCD display is now loose and will fall out of the front case if the case is tipped 3 Disconnect the RPG cable W12 at the A3 FPIB connector as indicated 4 Disconnect the A2 LCD to FPIB cable W113 at the A3 FPIB connector as indicated The A3 front panel interface board contains a Lithium ion battery Refer to Battery Disp...

Page 106: ...are fully extended on the back side of the A3 FPIB 8 Secure the A3 FPIB to the front case with nine new screws item 3 provided in the Repair and Re assembly Kit 9 Re connect the A2 LCD to FPIB cable W13 to the A3 FPIB connector as indicated Route the cable as shown 10 Re connect the RPG cable W12 to the A3 FPIB connector as indicated with the A2 LCD to A3 FPIB cable W13 passing beneath it as shown...

Page 107: ...ies 7 Figure 7 16 Replacing the A3 Front Panel Interface Board Replacing the Real Time Clock RTC Battery Located on the A3 Front Panel Interface Board FPIB The RTC battery is a Lithium ion battery and must be disposed of properly Refer to Battery Disposal on page 1 8 for important instructions on disposing of this battery ...

Page 108: ...Perform the steps under Post replacement Procedure on page 7 27 Figure 7 17 Replacing the RTC Battery Post replacement Procedure 1 Reinstall 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 28 2 Combine the front and rear cases Refer to Combin...

Page 109: ...on page 7 9 3 Disconnect the A5 system board to A3 FPIB cable W14 at the A3 FPIB connector If replacing this cable disconnect both ends 4 Lift the measurement group assemblies out of the front case and position them to the side of the front case as shown 5 Disconnect the A2 LCD to A5 system board cable W11 at the A5 system board connector It is necessary to first remove the adhesive tape that is o...

Page 110: ...Keysight N9923A Service Guide 7 29 Repair and Replacement Procedures Removing and Replacing the Measurement Group Assemblies Figure 7 18 Removing All Measurement Group Assemblies as One Unit ...

Page 111: ...ft the RF top panel over the type N RF connectors 6 Position the new RF top panel over the type N RF connectors and loosely reinstall the six screws item 1 Do not tighten these screws at this time they will be tightened after the front and rear cases have been combined 7 Connect cable W3 to the A5 system board connector There should be an audible click when the connector is fully in place 8 Positi...

Page 112: ...m shield 7 The PORT 2put cable can now be replaced by disconnecting the other end of the cable and removing it When installing the new cable do not tighten either of the cable connector nuts until both of them have been installed finger tight 8 Remove the RFI O ring 9 Remove the old insulator and install a new one 10 Position the new type N RF connector in the RF bottom shield making sure that it ...

Page 113: ...provided in the Repair and Re assembly Kit b Unplug the A6 SOM board from the A5 system board c Plug the new A6 SOM board into the A5 system board d Install four new screws item 3 from the Repair and Re assembly Kit and tighten them in the torque sequence indicated by the circled numbers in the illustration 4 To replace the flexible RF cables a To aid i n reinstallation note the connector to which...

Page 114: ...t touch the TCXO chip on the A5 system board 4 Clip cable W6 into each of the cable clamps on the A5 system board Cable W6 is the one with a red mark on each connector c To replace cable W5 or W7 1 Disconnect the appropriate cable and install the new cable being sure to position it as shown 5 To remove the I O panel refer to Replacing the I O Side Panel Doors and Gasket on page 7 14 6 Perform the ...

Page 115: ...7 34 Keysight N9923A Service Guide Repair and Replacement Procedures Removing and Replacing the Measurement Group Assemblies 7 Figure 7 21 Replacing the A6 SOM Board and Flexible RF Cables ...

Page 116: ... Re assembly Kit 8 Remove the waffle gasket from the RF bottom shield and discard it A new gasket is provided in the Repair and Re assembly Kit 9 Manipulate the new waffle gasket by hand to eliminate curling and install it on the RF bottom shield using the three dowel pins for alignment It is not necessary that the gasket be completely flat just enough to remain in position while installing the ne...

Page 117: ...easurement Group Assemblies 7 16 Remove the system board to FPIB cable from the old A5 system board and install it on the new board 17 Reinstall the I O side panel Refer to Replacing the I O Side Panel Doors and Gasket on page 7 14 18 Perform the steps under Post replacement Procedure on page 7 42 ...

Page 118: ...Keysight N9923A Service Guide 7 37 Repair and Replacement Procedures Removing and Replacing the Measurement Group Assemblies Figure 7 22 Replacing the A5 System Board ...

Page 119: ...not necessary to disconnect the cables from the A5 system board Refer to Replacing the A6 SOM Board and Flexible RF Cables on page 7 32 4 Remove the A5 system board Refer to Replacing the A5 System Board on page 7 35 5 Remove the BNC connector nut and washer from the old RF assembly and install them in the new RF assembly Note Cable W3 includes the BNC connector 6 Reinstall the A5 system board ont...

Page 120: ...Keysight N9923A Service Guide 7 39 Repair and Replacement Procedures Removing and Replacing the Measurement Group Assemblies Figure 7 23 Replacing the RF Assembly Including the A4 RF Board ...

Page 121: ...d cable at the system board connector and place a strip of adhesive tape over the connector to secure it This strip of adhesive tape is provided in the Repair and Re assembly Kit If necessary refer to Replacing the A2 LCD the LCD Shield and LCD Cables on page 7 22 4 Position the measurement group assemblies on top of the front case and align the I O side panel in the groove in the front case being...

Page 122: ...Keysight N9923A Service Guide 7 41 Repair and Replacement Procedures Removing and Replacing the Measurement Group Assemblies Figure 7 24 Replacing All Measurement Group Assemblies as One Unit ...

Page 123: ...e Measurement Group Assemblies 7 Post replacement Procedure 1 Reinstall the measurement group assemblies into the front case Refer to Reinstalling All Measurement Group Assemblies as One Unit on page 7 40 2 Combine the front and rear cases Refer to Combining the Front and Rear Cases on page 7 17 ...

Page 124: ...battery None needed None needed RPG None needed Manual check of RPG operation PORT 1 connector or associated cable W1 replaced or disturbed Error Terms Error Terms test PORT 2 connector or associated cable W2 replaced or disturbed Error Terms Error Terms test Front case including A1 keypad None needed Manual check of keyboard A2 LCD None needed Manual check of LCD A3 front panel interface board No...

Page 125: ...en the flash memory on the A6 SOM board is new or when the A6 SOM board memory has become corrupted Instructions for creating and using the SD card are available at the SD card for installing firmware link at keysight com find fieldfox2 Follow the repair calibration link Compare Serial Numbers Compare the serial number stored in the instrument memory with the serial number tag on the back of the i...

Page 126: ... 8 2 Service Related User Operations How to view options currently installed on your analyzer view the current firmware revision view the error log view temperature readings erase user data page 8 3 Options How to view the currently installed options re install options after repair page 8 5 Firmware Upgrades How to check your analyzer s current firmware revision where to locate additional informat...

Page 127: ...Supplemental Information 8 Supplemental Information Supplemental information for this service guide is available at http na support keysight com fieldfox serv_guide_supplement html This web site contains additional service information and is updated as new information becomes available ...

Page 128: ...udes the following information Model Number instrument model number Serial Number instrument serial number Firmware Release version of installed firmware Network Identity computer name and current IP address RF Serial Number serial number of RF PCA SB Serial Number serial number of System Board PCA FP Serial Number serial number of Front Panel PCA User Data Erased the most recent date and time Use...

Page 129: ... Temperature Related Information section of Chapter 5 for details Erase User Data Utility Press System 7 Press Service Diagnostics Press Advanced Press Erase User Data Press Confirm Erase The User Data memory portion is erased then the instrument restarts See the Firmware Related Information section of Chapter 5 for details on the Erase User Data utility ...

Page 130: ... Options If an instrument looses all of its options i e it reports or shows no options the only functionality available will be NA up to 4 GHz When the A6 SOM board is replaced it is necessary to re load the license files because the license and option information is stored on the A6 SOM board Process for obtaining and re installing options 1 Send an email to ctd soco_support keysight com with the...

Page 131: ...3A Service Guide General Purpose Maintenance and Service Procedures Options 8 3 Copy the license file to the root of a USB flash drive Follow the appropriate instructions in the N9923A Upgrade Installation Instructions ...

Page 132: ...firmware version is indicated on the Firmware Release line If the firmware upgrade process is interrupted memory contents in the instrument may become corrupted If a problem is suspected consider doing a fresh installation of the firmware Follow the process under Install Firmware from SD Card near the end of Chapter 7 See the Firmware Related Information section of Chapter 5 for details on what ha...

Page 133: ...A isopropyl alcohol or a high quality window cleaning solution Technique Do not rub back and forth with a polishing motion Use a single swipe from the soiled location to the nearest edge of the display Battery Maintenance See the Working with the Lithium Ion Battery section of the N9923A FieldFox RF Vector Network Analyzer User s Guide for information on the removable battery In particular see Bui...

Page 134: ... 7 6 battery RTC removal and replacement 7 21 before applying power 1 3 C calibration ANSI Z540 standards compliant Option A6J 2 6 commercial Option UK6 2 5 in CAT and NA modes 5 21 ISO 17025 standards compliant Option 1A7 2 5 one port 5 21 options available 2 5 QuickCal 5 21 two port 5 21 types 5 21 care of connectors 3 2 case group removal and replacement procedure 7 7 cases removal and replacem...

Page 135: ...ration 5 5 parts list 6 4 removal and replacement 7 21 LCD shield removal and replacement 7 21 lithium battery disposal 1 8 load instrument serial number 7 43 M main battery removal and replacement 7 6 maintenance battery maintenance 8 8 cleaning 2 2 cleaning the display 8 8 manual check keyboard 7 43 LCD 7 43 RPG 7 43 manual checks and procedures 7 43 measurement group operation 5 6 troubleshooti...

Page 136: ...mbers 6 4 listing of 6 4 miscellaneous analyzer part numbers 6 12 ordering information 6 2 replacement A1 keypad 7 7 A2 LCD 7 21 A3 front panel interface board 7 21 A5 system board 7 28 A6 SOM board 7 28 assembly cautions about 7 4 list of procedures 7 5 sequence 6 3 7 4 warnings about 7 4 case group procedure 7 7 CPU board 7 28 front panel group assemblies 7 21 LCD shield 7 21 main battery 7 6 me...

Page 137: ...ap handle removal and replacement 7 7 supplies ESD part numbers 6 13 support contacting Keysight 2 6 options 2 5 system board operation 5 9 T temperature battery pack 5 20 related information 5 20 screen 5 20 test equipment service 3 4 tools service part numbers 6 12 troubleshooting front panel group 4 7 measurement group 4 8 power up 4 6 where to begin 4 4 U upgrades firmware 5 23 user accessible...

Page 138: ...This information is subject to change without notice Keysight Technologies 2010 2015 September 2015 N9923 90018 N9923 90018 www keysight com ...

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