Keysight Technologies N1911A Service Manual Download Page 47

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Theory of Operation

Keysight N1911A/1912A Service Guide

PSU Assembly

Purpose

– Provides various DC power supplies

Inputs

– 100 Vac ~ 240 Vac, 50 Hz ~ 60 Hz, 150 VA Max [from an external source]
– Control lines [from front panel, via main board]

Outputs

– +12 Vdc [to main board]
– +5 Vdc [to main board]
– —5 Vdc [to main board]
– —12 Vdc [to main board]

Summary of Contents for N1911A

Page 1: ...Keysight N1911A 1912A P Series Power Meters Service Guide ...

Page 2: ...ights customarily provided to the public to use modify reproduce release per form display or disclose commercial computer software or commercial com puter software documentation No additional government requirements beyond those set forth in the EULA shall apply except to the extent that those terms rights or licenses are explicitly required from all providers of commercial computer software pursu...

Page 3: ...The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED KEYSIGHT TECHNOLOGIES SPECIFICALLY DISCLAIMS THE IMPLIED WAR...

Page 4: ...the instrument dangerous Intentional interruption is prohibited If this instrument is not used as specified the protection provided by the equipment could be impaired This instrument must be used in a normal condition in which all means of protection are intact only No operator serviceable parts inside Refer servicing to qualified personnel To prevent electrical shock do not remove covers For cont...

Page 5: ...nt is NOT isolated from the mains when the switch is pressed To isolate the instrument the mains coupler mains input cord should be removed from the power supply Direct current DC Both direct and alternating current Three phase alternating current Earth ground terminal Protective earth ground terminal Frame or chassis ground terminal Equipotentiality On mains supply Off mains supply Equipment prot...

Page 6: ...commended Calibration Interval Keysight Technologies recommends a two years calibration cycle for the N1911A and N1912A P Series power meter WARNING Before this instrument is switched on make sure it has been properly grounded through the protective conductor of the ac power cable to a socket outlet provided with protective earth contact Any interruption of the protective grounding conductor insid...

Page 7: ... the general environmental requirements for this instrument Environmental condition Requirement Temperature Operating condition 0 C to 55 C Storage condition 40 C to 70 C Humidity Operating condition Up to 95 RH at 40 C non condensing Storage condition Up to 90 RH at 65 C non condensing Altitude Up to 3000 m Pollution degree 2 ...

Page 8: ...tromagnetic Compatibility EMC compliances Safety compliance IEC 61010 1 2010 EN 61010 1 2010 3rd Edition Canada CAN CSA C22 2 No 61010 1 12 USA ANSI UL 61010 1 3rd Edition EMC compliance IEC 61326 1 2005 EN 61326 1 2006 CISPR11 2003 EN 55011 2007 Group 1 Class A Canada ICES NMB 001 Issue 4 June 2006 Australia New Zealand AS NZS CISPR 11 2004 ...

Page 9: ...e Canadian Standards Association This symbol is a South Korean Class A EMC Declaration This is a Class A instrument suitable for professional use and in electromagnetic environment outside of the home The RCM mark is a registered trademark of the Australian Communications and Media Authority This symbol indicates the time period during which no hazardous or toxic substance elements are expected to...

Page 10: ...Monitoring and Control Instrument product The affixed product label is as shown below Do not dispose in domestic household waste To return this unwanted instrument contact your nearest Keysight Service Center or visit http about keysight com en companyinfo environment takeback shtml for more information Sales and Technical Support To contact Keysight for sales and technical support refer to the su...

Page 11: ...ory Information 8 Safety compliance 8 EMC compliance 8 Regulatory Markings 9 Waste Electrical and Electronic Equipment WEEE Directive 2002 96 EC 10 Product category 10 Sales and Technical Support 10 1 Specifications Specifications and Characteristics 18 2 Performance Tests Introduction 20 Complete Equipment List 21 1 mW Power Reference Level Test 23 Description 23 Equipment 23 Test method 24 Outpu...

Page 12: ... Peak Path 31 Description 31 Equipment 31 Test method 31 Linearity Average Path 32 Description 32 Equipment 32 Test method 32 Absolute Accuracy Test Average Path 33 Description 33 Equipment 33 Test Method 34 Linearity Peak Path 37 Description 37 Equipment 37 Test method 37 Rise Fall Time Peak Path 38 Description 38 Equipment 38 Test method 39 3 Theory of Operation PPMC Assembly 42 Main Board Assem...

Page 13: ...rmance Test 55 Power Reference Level Adjustment Problems 56 Possible faults 56 Communication Interface Failures 57 Additional Diagnostic Tests 58 5 Repair Guide Introduction 60 Replaceable Parts 61 Front panel assembly 61 Main board assembly 69 PPMC processor PCI mezzanine assembly 70 DAP digital acquisition processing assembly 71 PSU power supply unit 72 Rear panel assembly 73 Additional spare pa...

Page 14: ... Instructions 104 Additional Repair Notes 109 Replacing a sensor flex assembly 109 Main board vs rear panel assembly 110 Replacing the PPMC Assembly 111 Replacing the Calibrator Semi Rigid Split Ferrite 112 6 Contacting Keysight Technologies Introduction 114 Contacting Keysight Technologies 114 Before Calling Keysight Technologies 115 Check the Basics 116 Instrument Serial Numbers 117 Returning Yo...

Page 15: ... Figure 2 3 Output SWR test setup open connection diagram 26 Figure 2 4 Output SWR test setup load connection diagram 26 Figure 2 5 Time base test setup connection diagram 28 Figure 2 6 Absolute accuracy test setup 34 Figure 2 7 Rise fall time test setup connection diagram 38 Figure 5 1 Calibrator assembly and improved calibrator assembly Figure 5 20 Creating a sharp bend 109 ...

Page 16: ...16 Keysight N1911A 1912A Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 17: ...Keysight N1911A 1912A P Series Power Meters Service Guide 17 1 Specifications Specifications and Characteristics 18 This chapter provides the power meter s specifications ...

Page 18: ... Keysight N1911A 1912A Service Guide Specifications and Characteristics For the characteristics and specifications of the N1911A 1912A refer to the data sheet at http literature cdn keysight com litweb pdf 5989 2471EN pdf ...

Page 19: ... 23 Output Standing Wave Ratio SWR Test 25 Time Base Frequency Accuracy 28 Zero Set Average Path 30 Zero Set Peak Path 31 Linearity Average Path 32 Absolute Accuracy Test Average Path 33 Linearity Peak Path 37 Rise Fall Time Peak Path 38 This chapter contains procedures which allow you to test the power meter s electrical performance to its specifications ...

Page 20: ...ower Reference Output Time Base Frequency Accuracy Zero Set Average Path Zero Set Peak Path Linearity Average Path Linearity Peak Path Rise Fall Time Peak Path NOTE This document does not provide a complete breakdown for these tests it only gives a brief overview of each in line with Keysight s recommendation that the Keysight N7832A calibration software should be used at all times Performance tes...

Page 21: ...te time 10 seconds 53132A 53131A Meters Power meter Dual channel Absolute accuracy 0 5 Power reference accuracy 0 9 a best capability measurement is required for the Power Reference Output the power level must be accurately measured and the uncertainty of this measurement must also be known E4419B E4419A Power sensor 2 required Frequency 50 MHz Amplitude range 70 dBm to 20 dBm SWR 1 15 at 50 MHz 8...

Page 22: ...splitter required Frequency DC to 6 GHz Insertion loss 6 to 7 dB 3 GHz SWR 1 1 10 MHz to 2 GHz 1 3 2 GHz to 3 GHz 11667A Option 001 BNC cable Frequency DC to 10 GHz 50 Ω coax BNC m both ends 120 cm 48 in 10503A Calibration test cable required for N1912A N1912 61017 Sensor cable required 11730A N Type calibration kit 85032B Assorted accessories cables and adapters required Instrument Critical speci...

Page 23: ...17A power meter to the DUT reference Equipment Required test equipment 1 unit of E4419B or E4417A dual channel power meter 1 unit of 8482A power sensor 11730A power sensor cable Either of these E4419B or E4417A power meters can be used This specific power sensor model must be used Figure 2 1 1 mW power reference level test setup connection diagram Ch A POWER METER P SERIES POWER METER NOTE For rea...

Page 24: ... and the 8482A sensor measure the 1 mW power reference of the DUT 4 Using all of these values the N7832A software will calculate the power reference level of the DUT NOTE The 1 mW reference of the E4419B or E4417A power meter must be precisely calibrated at a standards accredited lab and the uncertainty of this measurement known Anyone who has a basic understanding of metrology should be able to p...

Page 25: ...network analyzer 1 unit of 85032B Type N calibration kit 1 unit of E4419B or E4417A dual channel power meter 2 unit of 8481D power sensor 2 unit of 11667A 001 power splitter 1 unit of 20 dB pad male to female e g 8491A 1 unit of 30 dB pad e g 11708A reference attenuator 2 unit of 11730A power sensor cable An alternative network analyzer can be used as long as it can measure S11 in the 45 MHz 55 MH...

Page 26: ...ram Figure 2 4 Output SWR test setup load connection diagram POWER METER POWER SENSOR Load port 20 dB TYPE N MALE PORT ATTENUATOR 30 dB ATTENUATOR POWER SPLITTERS CH A CH B Ch A POWER METER P SERIES POWER METER POWER SENSOR TYPE N MALE OPEN Load port 20 dB ATTENUATOR Ch A POWER METER P SERIES POWER METER POWER SENSOR TYPE N MALE LOAD Load port 20 dB ATTENUATOR ...

Page 27: ...em terminate it with the 50 R load from the 85032B calibration kit and repeat the 1 mW power reference level measurement 5 Using all of these values the N7832A software will calculate the VSWR of the power reference output NOTE For rear panel options the connections will differ from the illustration shown here Refer to the connector identification markings on the rear panel for further details NOT...

Page 28: ...rectly measured by a frequency counter Equipment Required test equipment 1 unit of 53132A frequency counter 10 MHz frequency standard 1 unit of 10503A BNC cable An alternative frequency counter can be used as long as it has the appropriate bandwidth 10 MHz Figure 2 5 Time base test setup connection diagram Ch A FREQUENCY COUNTER P SERIES POWER METER Channel 1 Ref In 10 MHz standard Trigger output ...

Page 29: ...nfigured manually via the command SERV BIST TBAS STAT ON which enables the 10 MHz feed to the trigger output connector refer to the programming guide for further details on the use of this command This test can also be configured manually via the front panel access the Service menu select Self Test and select Time Base to enable the 10 MHz feed to the trigger output connector No adjustment is avai...

Page 30: ... value Equipment No test equipment required Test method 1 Execute the internal zero set measurement procedure for channel A 2 Read back the result of the measurement from the DUT 3 If the DUT model number is N1912A then repeat this procedure for channel B 4 The test will take a few minutes to complete 5 The measurement result should be less than 0 0000175 The smaller the measurement result the sma...

Page 31: ...alue Equipment No test equipment required Test method 1 Execute the internal zero set measurement procedure for channel A 2 Read back the result of the measurement from the DUT 3 If the DUT model number is N1912A then repeat this procedure for channel B 4 The test will take a few minutes to complete 5 The measurement result should be less than 0 015 The smaller the measurement result the smaller t...

Page 32: ...ment required Test method 1 Execute the internal linearity measurement procedure for channel A 2 Read back the result of the measurement from the DUT 3 If the DUT model number is N1912A then repeat this procedure for channel B 4 The test will take a few minutes to complete 5 The measurement result should be less than 0 5 and greater than 0 5 The optimum measurement result for this test is 0 NOTE T...

Page 33: ...measure the power sensor voltage and display the appropriate power level Equipment Required test equipment 1 unit of 3458A digital multimeter 1 unit of 33250A function generator 1 unit of 11683A Option H01 range calibrator 1 unit of 11730A power sensor cable 2 units of 10503A BNC cable 1 unit of BNC T joint connector BNC female male female 1 unit of BNC female to dual banana connector ...

Page 34: ...e calibrator to operate properly 11683A range calibrator front panel 11683A range calibrator rear panel BNC T joint connector BNC cable BNC cable N1911 1912A P Series power meter 3458A digital multimeter 33250A function generator Banana connector Banana connector NOTE The procedure details the key presses required on the Keysight N1911A P Series power meter For the Keysight N1912A P Series power m...

Page 35: ...age input and the voltmeter using cables and a BNC T joint connector at the range calibrator 9 Configure the DUT as shown below 10 Configure the voltmeter using the default setup settings NOTE When switching the range calibrator to STANDBY allow enough time for the range calibrator to settle to its zero value before attempting to zero the Keysight N1911A 1912A P Series power meter This settling wo...

Page 36: ...uracy of the N1911A 1912A in a table as shown below Effective power DC voltage Voltmeter range Power meter filter voltmeter NRDNS CH A error CH B error Specification 12 dBm 0 00565 V 0 1 V 256 0 5 5 dBm 0 02834 V 0 1 V 64 0 5 5 dBm 0 28400 V 1 V 64 0 5 8 dBm 0 56700 V 1 V 16 0 5 10 dBm 0 90100 V 1 V 16 0 5 12 dBm 1 43500 V 10 V 16 0 5 14 dBm 2 29000 V 10 V 16 0 5 16 dBm 3 66700 V 10 V 16 0 5 17 dB...

Page 37: ... the result of the measurement from the DUT 3 If the DUT model number is N1912A then repeat this procedure for channel B 4 The test will take a few minutes to complete 5 The measurement result should be less than 0 8 and greater than 0 8 The optimum measurement result for this test is 0 NOTE This test can be performed manually via the commands SERV BIST PEAK 1 2 LIN 0 SERV BIST PEAK 1 2 LIN PERR R...

Page 38: ...signal which is then compared with defined acceptance limits Overshoot settling time and pulse recovery are also characterized Equipment Required test equipment 1 unit of 81130A pulse data generator mainframe 2 unit of 81131A output modules installed in 81130A 2 unit of N1912 61017 calibration test cable 2 unit of 10503A BNC cable 2 unit of adapter BNC to SMC Figure 2 7 Rise fall time test setup c...

Page 39: ...the 10 and 90 crossover points occur for both edges 5 Using the times obtained for the 10 90 crossovers the N7832A software will calculate the rise fall time performance of the DUT NOTE For rear panel options the connections will differ from the illustration shown here Refer to the connector identification markings on the rear panel for further details NOTE Only 1 cable is required if the DUT is a...

Page 40: ...2 Performance Tests 40 Keysight N1911A 1912A Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 41: ...rs Service Guide 41 3 Theory of Operation PPMC Assembly 42 Main Board Assembly 43 DAP Assembly 44 Calibrator Assembly 45 Front Panel Assembly 46 PSU Assembly 47 This chapter describes how each of the power meter s individual assemblies operate ...

Page 42: ...Stores the power meter firmware in flash EEPROM Stores the power meter serial number and option data Inputs Power supplies from PSU via main board Control and data lines from main board DAP s and front panel LAN USB communications from external equipment GPIB communications from external equipment via main board Outputs Control address and data lines to main board DAP s and front panel ...

Page 43: ...rialiser for the LCD display Provides signal routing between the PPMC DAP s and front panel Inputs Power supplies from PSU Sensed power level s from sensor flexi s Trigger input from external equipment Control address and data lines from PPMC Outputs Processed average path measurement to PPMC Unprocessed peak path measurement samples to DAP s Trigger output recorder output s to external equipment ...

Page 44: ... processing for the peak measurement path of a channel Inputs Power supplies from PSU via main board Unprocessed peak path measurement samples from main board Control address and data lines from PPMC Outputs Processed peak path measurement data to PPMC via main board Control and data lines to PPMC via main board ...

Page 45: ...brator Assembly Purpose Provides a 1 mW 0 dBm power reference level at 50 MHz Inputs Power supplies from PSU via main board Control address and data lines from PPMC Outputs 1 mW 0 dBm power reference to external equipment Control and data lines to PPMC via main board ...

Page 46: ...assist with manual setups and measurements Provides mounting for the sensor and power reference connectors option 101 Inputs Power supplies from PSU via main board Front panel control interface from the PPMC LVDS LCD control lines via main board Outputs Keypress data to PPMC via main board Information on the LCD display Control and data lines to PPMC via main board ...

Page 47: ... PSU Assembly Purpose Provides various DC power supplies Inputs 100 Vac 240 Vac 50 Hz 60 Hz 150 VA Max from an external source Control lines from front panel via main board Outputs 12 Vdc to main board 5 Vdc to main board 5 Vdc to main board 12 Vdc to main board ...

Page 48: ...3 Theory of Operation 48 Keysight N1911A 1912A Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 49: ...blems 51 Instrument Self Test 52 Extended Self Test 54 Performance Test 55 Power Reference Level Adjustment Problems 56 Communication Interface Failures 57 Additional Diagnostic Tests 58 This chapter contains troubleshooting flow charts designed to isolate faults in the Rmt I O GP IB and RS232 422 interface ports ...

Page 50: ...pected faults with the power meter Rmt I O Remote Input Output signal lines and RS232 422 serial port If there is a problem when attempting to use the RS232 422 serial interface or the remote I O functions consult the user s guide and confirm that all the user setups are correct before proceeding with the following fault finding flowcharts ...

Page 51: ...tional Basic internal checks Check reseat the cable between the line module and the PSU Check reseat the cable between the PSU and the main board Green LED DS1 If this is off then the PSU may be faulty Green LED DS4 This should come on when the power button is pressed Green LEDs DS2 DS3 These will flash on and off during normal operation Possible faults PSU Main board Front panel defective keymat ...

Page 52: ...d low probability Battery Checks that the lithium manganese battery on the main board is working Replace the battery to see if this clears the fault Note It is recommended for the battery to be replaced at the Keysight service center every five years Lithium manganese battery high probability Main board low probability Peak path ChA peak path Verifies that the peak path of channel A is working Not...

Page 53: ...nel B low probability Main board high probability ChB CW path Verifies that the average path of channel B is working Note This does not prove that the average path meets its specifications Not applicable Main board ChB DAP check Executes an internal self test procedure on the DAP assembly for channel B Replace the DAP assembly for channel B to see if this clears the fault DAP assembly channel B hi...

Page 54: ...le Front panel defective keymat or key flex circuit Bitmap display Verifies that all pixels in the display can be illuminated in various colors Not applicable Front panel defective display display interface board or inverter board Time base Provides a means to measure time base frequency accuracy Check that the BNC cable being used is not damaged Check that the BNC is connected to Trig Out not Tri...

Page 55: ...ng used is not damaged Check that the BNC is connected to Trig Out not Trig In Main board Zero set average Path failures Not applicable Main board Zero set peak path failures Not applicable Main board Linearity average path failures Not applicable Main board Linearity peak path failures Replace the DAP assembly for the channel to see if this clears the fault DAP assembly low probability main board...

Page 56: ...4 Troubleshooting Guide 56 Keysight N1911A 1912A Service Guide Power Reference Level Adjustment Problems Possible faults Calibrator assembly high probability Main board low probability ...

Page 57: ...tion Debug tips Possible faults GPIB communication Check reseat the ribbon cable connecting the PPMC to the main board Ribbon cable low probability PPMC assembly low probability Main board high probability LAN USB communication Check visually to see whether or not the connector is obstructed damaged PPMC assembly ...

Page 58: ...lts USB LAN functionality The N7832A software only tests functionality over GPIB Check the DUT responds when RST is sent to it via the USB LAN interfaces PPMC assembly Sensor functionality The N7832A software does not prove both paths of the sensor flex assembly Connect an E4412A sensor to the DUT and ensure it can be zeroed calibrated Sensor flex assembly ...

Page 59: ...ructions 85 Reassembly Instructions 93 Disassembly vs Part Replacement 96 Front Panel Disassembly Instructions 99 Front Panel Reassembly Instructions 104 Additional Repair Notes 109 Replacing the PPMC Assembly 111 Replacing the Calibrator Semi Rigid Split Ferrite 112 This chapter details the power meter s replaceable parts It also explains how to assemble and disassemble the power meter ...

Page 60: ...aceable Parts 2 Tools Required 3 Disassembly Instructions 4 Reassembly Instructions 5 Disassembly vs Part Replacement 6 Front Panel Disassembly Instructions 7 Front Panel Reassembly Instructions 8 Additional Repair Notes 9 Replacing the PPMC Assembly 10 Replacing the Calibrator Semi Rigid Split Ferrite To order parts contact your local Keysight Technologies Sales and Service Office To return your ...

Page 61: ...nel Option is available to move the reference calibrator to rear panel Keysight part number Description Visual N1912 61804 Front panel assembly front calibrator option N1912 61805 Front panel assembly rear calibrator option Note The front panel assembly must be customized to suit the hardware configuration of the unit being repaired Refurbished front panel assemblies are not available ...

Page 62: ...nel plug large 1 unit of N1911A font panel dress label 1 unit of N1911A nameplate N1912 61806 N1912 21003 N1912 21004 N1912 00026 N1911 80001 N1911A front connectors option 2 unit of front panel plug large 1 unit of front panel Plug small 1 unit of blank front panel dress label 1 unit of N1911A nameplate N1912 21004 N1912 21005 N1912 00025 N1911 80001 N1912A front connectors option 2 unit of senso...

Page 63: ...ame assembly is used for all four sensor positions The kit includes a spacer required for fitting the flex to the rear panel The sensor flex assembly is supplied straight and so it must be folded to match the assembly being replaced see Additional Repair Notes on page 109 N1912 21003 Calibrator plug N1912 21005 Front panel plug small N1912 21004 N1912 21005 ...

Page 64: ...umber Description Visual N1912 00025 N1912 00026 N1912 00027 Blank front panel dress label N1911A front panel dress label N1912A front panel dress label N1911 80001 N1912 80003 N1911A nameplate N1912A nameplate N1912 00025 N1912 00027 N1912 00026 N1911 80001 N1912 80003 ...

Page 65: ...0003 Front panel sub frame Note This front panel sub frame is used on all variants of the front panel assembly N1912 40002 Display support molding Note This display support molding is used on all variants of the front panel assembly N1912 40001 Keymat Note This keymat is used on all variants of the front panel assembly ...

Page 66: ...cuit is used on all variants of the front panel assembly N1912 20005 EMI shielded window Note This EMI shielded window is used on all variants of the front panel assembly N1912 00002 EMI screen Note This EMI screen is used on all variants of the front panel assembly Keysight part number Description Visual ...

Page 67: ...ed on all variants of the front panel assembly and must be ordered together with the DC to DC converter 0950 5724 N1912 60002 Display interface board Note This display interface board is used on all variants of the front panel assembly Keysight part number Description Visual Front view Rear view ...

Page 68: ...e front panel assembly and must be ordered together with the display 2090 1101 N1912 61002 Backlight cable assembly Note This backlight cable assembly is used on all variants of the front panel assembly N1912 00038 Split washer Note This split washer is used on all variants of the front panel assembly Keysight part number Description Visual ...

Page 69: ...911A main board assembly new N1911A main board assembly video output option Option H01 N1912 61801 non video output option N1912 66501 video output option N1912A main board assembly new N1912A main board assembly video output option Option H01 Note Refurbished main boards are not available The part number for the lithium manganese battery Upper right of both photographs is 1420 0394 ...

Page 70: ...assembly is used for both N1911A and N1912A models N1911 66500 single channel PPMC PCA comes pre programmed with N1911A firmware N1912 66500 dual channel PPMC PCA comes pre programmed with N1912A firmware Refurbished PPMC assemblies are not available The PPMC assembly must be programmed once it has been installed see Additional Repair Notes on page 109 Ribbon cable 8121 1076 is supplied separately...

Page 71: ...n processing assembly Keysight part number Description Visual N1912 60004 Measurement board Note The same assembly is used for both N1911A and N1912A models Two identical DAP assemblies are fitted to the N1912A model Refurbished DAP assemblies are not available Top bottom views ...

Page 72: ...y unit Keysight part number Description Visual N1912 61808 Power supply assembly kit new Note The same assembly is used for both N1911A and N1912A models Refurbished PSUs are not available Cables N4010 61846 and N4010 61845 are supplied separately N4010 61846 N4010 61845 ...

Page 73: ... customized to suit the hardware configuration of the unit being repaired Refurbished rear panel assemblies are not available Parts N1912 61007 and N1912 61031 differ slightly with regards to the connector cutout positions The revision of the main board can be used to help determine which rear panel assembly is in use see Additional Repair Notes on page 109 The same assemblies are used for both N1...

Page 74: ...ibrator 6960 0081 6960 0024 6960 0178 N1911A front connectors option 1 unit of sensor flex assembly 1 unit of N Type connector 1 unit of lock washer 1 unit of hex nut 1 unit of washer 1 unit of rear panel plug BNC 1 unit of rear panel plug Sensor N1912 61806 E4418 20009 E4418 00016 2950 0132 3050 0916 6960 0081 6960 0024 N1912A front connectors option 1 unit of Recorder Output Cable 2 unit of rear...

Page 75: ...ustomization parts Keysight part number Description Visual E4418 20009 E4418 00016 2950 0132 3050 0916 N Type connector Lock washer Hex nut Washer N1912 61806 Sensor flex assembly E4418 61015 Recorder output cable 3050 0916 2950 0132 E4418 00016 E4418 20009 ...

Page 76: ... N1911A 1912A Service Guide 6960 0081 6960 0024 6960 0178 Rear panel plug BNC Rear panel plug sensor Rear panel plug calibrator Keysight part number Description Visual Two views shown for each part 6960 0178 6960 0024 6960 0081 ...

Page 77: ...Repair Guide 5 Keysight N1911A 1912A Service Guide 77 Additional spare parts Keysight part number Description Visual N1912 61036 Line module N4010 21025 Service connector cable ...

Page 78: ...brator assembly front connectors option For more information on the improved calibrator assembly refer to Improved calibrator assembly on page 79 N1911 61002 Calibrator assembly rear connectors option Note Semi rigid cable N1912 61004 is not included with assembly N1911 61002 if this is required it is available as a separate item ...

Page 79: ...tor for a better fit with the front panel assembly as shown in Figure 5 1 The calibrator plug N1912 21003 will not be needed with the improved calibrator assembly Figure 5 1 Calibrator assembly and improved calibrator assembly NOTE The N1911A N1912A performance will not be affected with the improved calibrator assembly Improved calibrator assembly Calibrator assembly ...

Page 80: ...5 Repair Guide 80 Keysight N1911A 1912A Service Guide Outer housing components Keysight part number Description Visual 5041 7717 Clamshell top 5041 7718 Clamshell bottom N1912 61005 Fan assembly ...

Page 81: ...Repair Guide 5 Keysight N1911A 1912A Service Guide 81 N1912 61025 Cable clamp 34401 86020 Bumper kit 34401 45021 Handle Keysight part number Description Visual ...

Page 82: ...ual N1911 61004 N1912 80005 Calibrator semi rigid cable rear option Split ferrite Note If the semi rigid cable is replaced then the split ferrite must be positioned correctly see Additional Repair Notes on page 109 2110 0957 Line module fuse 3 15 A 250 V non time delayed N1911 61004 with N1912 80005 ...

Page 83: ...brated to 0 34 Nm 3 lb in T6 T8 T10 T20 Torx screwdriver bits 7 16 break spanner calibrated to 2 37 Nm 21 lb in 5 16 break spanner calibrated to 1 02 Nm 9 lb in 9 32 socket N1912 61807 Special tooling kit Contains ODU socket Trigger socket 9 16 BNC socket Sockets must be used in conjunction with a drive torque wrench calibrated to 2 37 Nm 21 lb in The 9 16 BNC socket is required to remove the Trig...

Page 84: ...T20 screwdriver 2 37 Nm Attach PPMC DAP assemblies to main board T8 screwdriver 0 56 Nm Fit calibrator semi rigid both ends Option 003 5 16 spanner 1 02 Nm Attach earth wires Nut 9 32 socket 1 02 Nm Attach earth wires Screw T20 screwdriver 2 37 Nm Attach top clamshell to bottom clamshell T20 screwdriver 2 37 Nm Fit sensor connector Special tooling kit N1912 61807 2 37 Nm Fit PSU PSU safety cover T...

Page 85: ...power reference connectors Additional information is provided to assist in the disassembly of Option 003 units i e with rear panel sensor and power reference connectors Remove the handle Rotate it to the vertical position Pull both sides outwards from the body of the unit Remove the front rear bumpers Pull one side of the bumper outwards to disengage it Pull it away from the unit Separate the clam...

Page 86: ...ors from the top clamshell Remove top clamshell Figure 5 3 Remove the PSU safety cover Figure 5 4 Use the T10 Torx screwdriver bit to remove the 4 screws attaching the PSU safety cover to the top clamshell Lift and remove the safety cover Remove the PSU cable guide Figure 5 4 Use the T10 Torx screwdriver bit to remove the screw attaching the cable guide to the top clamshell Lift and remove cable g...

Page 87: ... 6 and Figure 5 7 1 Front panel assembly 2 Calibrator assembly 3 Sensor RF connections 4 Sensor flex connection s 5 Calibrator cable connection 6 Cable clamp 7 Rear panel assembly 8 Line module 9 Fan assembly 10 Analog recorder output connection s 11 Service connector cable 12 Ribbon cable 13 PPMC assembly 14 DAP assembly Channel A 15 DAP assembly Channel B Figure 5 6 Instructions Visual 12 9 8 10...

Page 88: ... board Disconnect the sensor flex connection s from the main board Disconnect the calibrator cable connection from the main board Disconnect the analog recorder output connection s from the main board Figure 5 7 Remove the EMI earth wires Figure 5 8 Use the 9 32 Socket to remove the hex nut attaching the EMI earth wires to the calibrator assembly Remove the earth wires and washers taking note of t...

Page 89: ...epress both sides of the connector holding the ribbon cable to eject it Figure 5 9 Disconnect the semi rigid cable Figure 5 10 Note This only applies to Option 003 units Use the 5 16 spanner to disconnect the semi rigid cable from the N Type connector on the rear panel Figure 5 10 Instructions Visual ...

Page 90: ...1 Carefully lift and remove the front panel assembly Figure 5 11 Disconnect PPMC cables Figure 5 6 Figure 5 7 Disconnect the service connector cable from the PPMC assembly Disconnect the ribbon cable from the main board whilst leaving it connected to the PPMC assembly Instructions Visual ...

Page 91: ...assembly Carefully remove each DAP assembly by lifting the end closest to the rear panel Figure 5 12 Remove the main board Figure 5 13 Use the T20 Torx screwdriver bit to remove the 5 screws attaching the main board to the bottom clamshell Use the T20 Torx screwdriver bit to remove the screw attaching the earth wires to the line module Remove the earth wires and washers taking note of the assembly...

Page 92: ...move the rear panel Figure 5 14 Use the N1912 61807 special tooling kit to remove the fasteners on the trigger connectors Use the 9 32 socket to remove the GPIB standoffs Carefully pull the rear panel away from the main board Figure 5 14 Instructions Visual ...

Page 93: ... option 101 or 003 is fitted The main board connector from the PSU must be pushed firmly to fully engage it Take care not to trap any cables when fitting the top clamshell Analog recorder output connections Figure 5 15 Ensure recorder 1 is plugged into the rear connector Where applicable recorder 2 is plugged into the connector nearer the front Figure 5 15 Sensor flex connections Figure 5 16 A Fro...

Page 94: ...ck White cable G Channel B Black cable H Channel B Black White cable Note Only connect E and F for N1911A Connect E F G H for N1912A Figure 5 17 PSU screw locations Figure 5 18 A Attach PSU to clamshell 6 screws B Attach PSU cable guide 1 screw C Attach PSU safety cover 4 screws Figure 5 18 Instructions Visual E F G H C A A C B ...

Page 95: ...r Guide 5 Keysight N1911A 1912A Service Guide 95 PSU cable routing Figure 5 19 Ensure the PSU cables are positioned such that the cable guide does not trap them or pinch them Figure 5 19 Instructions Visual ...

Page 96: ...w be removed PPMC assembly front connectors option Remove handle bumpers and top clamshell including PSU Disconnect the main board ribbon cable from the PPMC Disconnect the service connector cable from the PPMC Remove the 4 screws securing the PPMC to the main board PPMC assembly can now be removed PPMC assembly rear connectors option Remove handle bumpers and top clamshell including PSU Disconnec...

Page 97: ...rews securing the DAP assembly to the main board DAP assembly can now be removed DAP assembly Channel B Remove handle bumpers and top clamshell including PSU Remove the 4 screws securing the DAP assembly to the main board DAP assembly can now be removed Front panel assembly front connectors option Remove handle bumpers and top clamshell including PSU Disconnect the sensor RF connections from the m...

Page 98: ...from the front panel Front panel assembly can now be removed Sensor flex assembly front connectors option Remove front panel assembly as previously described Use the N1912 61807 special tooling kit to remove the sensor flex assembly Sensor flex assembly rear connectors option Remove handle and front rear Bumpers Remove top clamshell including PSU Disconnect the sensor RF connections from the main ...

Page 99: ... that it may not be necessary to completely disassemble the front panel in order to repair or replace some of its parts As such this procedure should be tailored to suit the specific repair requirements Step 1 Carefully lift and remove the calibrator plug This step does not apply to units with rear panel connectors This step is only applicable for calibrator assembly with the calibrator plug For m...

Page 100: ...e display interface board and then disconnect it Step 3 Disconnect the white plastic plug from the display interface board Step 4 Unlock the main plastic clip that holds the front panel sub frame and display support molding together situated beside the key flex circuit and carefully pull them apart to separate them Instructions Visual Flex cable White plastic plug ...

Page 101: ... screws that attach the display to the display support molding and then disconnect it from the display interface board Step 6 Lift the display interface board off of the plastic mounting lugs on the display support molding to separate them from one another Instructions Visual ...

Page 102: ... them from one another Note Take care not to damage the EMI spring fingers on the calibrator assembly Step 8 Disconnect the backlight cable assembly from the display interface board and inverter board Step 9 Remove the 2 screws that attach the display inter face board to the inverter board and separate them from one another Instructions Visual EMI spring finger ...

Page 103: ...ng the EMI screen to the front panel sub frame and separate them from one another Step 11 Disengage the rubber tabs that attach the key flex circuit to the keymat and carefully lift it out Step 12 Remove the EMI shielded window and the keymat from the front panel sub frame Instructions Visual ...

Page 104: ...uctions Visual Step 1 Insert the keymat into the front panel Sub frame Step 2 Insert the EMI shielded window into the keymat ensuring that it is clean and free from fingerprints Step 3 Overlay the key flex circuit onto the keymat ensuring that all of the rubber lugs are engaged to hold it securely ...

Page 105: ...e 105 Step 4 Overlay the EMI screen onto the key flex circuit ensuring that all of the metal tabs are engaged to hold it securely Step 5 Fit the display interface board onto the plastic mounting lugs on the display support molding Instructions Visual ...

Page 106: ...splay interface board using the backlight cable assembly Note The cable must be tucked under the plastic clip to prevent any fouling Step 8 Attach the calibrator assembly to the display support molding using the 3 screws removed earlier Step 9 Carefully spread the EMI fingers outwards ensuring they extend beyond the edges of the hole in which the calibrator assembly is fitted Instructions Visual ...

Page 107: ...uide 107 Step 10 Fit the split washer to the calibrator assembly Step 11 Attach the display to the display interface board using the 4 screws removed earlier Step 12 Connect the white plastic plug to the display interface board Instructions Visual ...

Page 108: ...e engaged to hold it securely Step 14 Connect the flex cable to the display interface board and then tighten the locking tab Step 15 Re fit the calibrator plug This step is only applicable for calibrator assembly with the calibrator plug For more information on the improved calibrator assembly refer to Improved calibrator assembly on page 79 Instructions Visual ...

Page 109: ... bent after heat has been applied to it i e using a hot air gun or a similar device Figure 5 20 Creating a sharp bend NOTE Once this sharp bend has been created the flex should not be bent at this point again to do so may break the tracking within the flex Route and connect the sensor flex assembly once the sensor flex assembly has been attached to the power meter it should be folded to match the ...

Page 110: ...on 103 there are TWO different rear panels Revision 102 main boards are not available as spares all spare main boards will be revision 103 or newer When replacing a revision 102 main board take note that the rear panel will need to be replaced Figure 5 21 and Figure 5 22 show where to find the main board revision markings Figure 5 21 Figure 5 22 Main board revision 102 Main board revision 103 ...

Page 111: ...be stored in the PPMC assembly via the command SERV SNUM CHARACTER DATA Instrument option s This these can be stored in the PPMC assembly via the command SERV OPT CHARACTER DATA Refer to the Programming Guide for further details on the use of these commands NOTE Fitting a PPMC assembly that has been pre programmed with N1912A firmware to an N1911A power meter will generate errors these errors will...

Page 112: ... 23 Position the ferrite such that it s furthest edge is 120 mm 4 from the bend of the semi rigid Figure 5 24 Hold the ferrite in place by applying a coating of silicone or silicone rubber compound e g RTV along that 20 mm section of the semi rigid Join both halves of the ferrite keeping the mating surfaces free of the silicone compound if possible Figure 5 23 Figure 5 24 ...

Page 113: ...ng Keysight Technologies Introduction 114 Before Calling Keysight Technologies 115 Check the Basics 116 Instrument Serial Numbers 117 Returning Your Power Meter for Service 118 Useful Web Pages 119 This chapter details what to do if you have a problem with your power meter ...

Page 114: ...age titled Before Calling Keysight Technologies on page 115 This section contains a checklist that helps identify some of the most common problems If you wish to contact Keysight Technologies about any aspect of the power meter from service problems to ordering information refer to Sales and Technical Support on page 10 If you wish to return the power meter to Keysight Technologies refer to the se...

Page 115: ...r meter is covered by a separate maintenance agreement please be familiar with the terms Keysight Technologies offers several maintenance plans to service your power meter after warranty expiration Call your Keysight Technologies Sales and Service Center for full details If the power meter becomes faulty and you wish to return the faulty instrument follow the description on how to return the fault...

Page 116: ...cket has power Check that the power meter is plugged into the proper ac power source Check that the power meter is switched on Check that the line fuse is in working condition Check that the other equipment cables and connectors are connected properly and operating correctly Check the equipment settings in the procedure that was being used when the problem occurred Check that the test being perfor...

Page 117: ...ed to the rear of each Keysight Technologies instrument This label has two instrument identification entries The first provides the instruments serial number and the second provides the identification number for each option built into the instrument The serial number is divided into two parts the prefix two letters and the first four numbers and the suffix the last four numbers The prefix letters ...

Page 118: ...o 4 inches on all sides of the power meter for packing material Surround the power meter with at least 3 to 4 inches of packing material or enough to prevent the power meter from moving in the carton If packing foam is not available the best alternative is SD 240 Air Cap TM from Sealed Air Corporation Commerce CA 90001 Air Cap looks like a plastic sheet covered with 1 1 4 inch air filled bubbles U...

Page 119: ...om find pseriesmanuals Product firmware www keysight com find pseriesfirmware Performance test calibration software www cal software keysight com Service notes N1911A https servicenotes literature keysight com litapp SearchSN do method ope nExternalSNSearch prodNum N1911A N1912A https servicenotes literature keysight com litapp SearchSN do method ope nExternalSNSearch prodNum N1912A ...

Page 120: ...6 Contacting Keysight Technologies 120 Keysight N1911A 1912A Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 121: ... is subject to change without notice Always refer to the Keysight website for the latest revision Keysight Technologies 2006 2017 Edition 19 November 17 2017 Printed in Malaysia N1912 90015 N1912 90015 www keysight com ...

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Keysight Technologies N1911A, Service Manual

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