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Keysight U3401A 4 ½ Digit Dual Display Multimeter
User’s and Service Guide

83

5

Disassembly and Repair

Operating Checklist     

84

Types of Service Available     

85

Mechanical Disassembly     

89

Replaceable Parts     

95

This chapter will help you troubleshoot a faulty multimeter. It describes how to 

disassemble the multimeter, how to obtain repair services, and lists the 

replaceable parts.

Summary of Contents for U3401A

Page 1: ...Keysight U3401A 4 1 2 Digit Dual Display Multimeter User s and Service Guide ...

Page 2: ... rights customarily provided to the public to use modify reproduce release perform display or disclose commercial computer software or commercial computer 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: ...Caution risk of danger refer to this manual for specific Warning or Caution information Both direct and alternating current Out position of a bi stable push control Earth ground terminal In position of a bi stable push control Protective earth ground terminal Frame or chassis ground terminal IEC Measurement Category II Measurement performed on circuits that are directly connected to the low voltag...

Page 4: ... check the multimeter s operation by measuring a known voltage For current measurement turn off circuit power before connecting the multimeter to the circuit Always place the multimeter in series with the circuit When connecting probes always connect the common test probe first When disconnecting probes always disconnect the live test probe first Do not measure more than the rated voltage as marke...

Page 5: ...e power and do not use the product until safe operation can be verified by service trained personnel If necessary return the product to Keysight Technologies Sales and Service Office for service and repair to ensure the safety features are maintained CAUTION Turn off circuit power and discharge all high voltage capacitors in the circuit before you perform resistance continuity diodes or capacitanc...

Page 6: ...umidity Full accuracy up to 80 R H Relative humidity for temperature up to 28 C Storage temperature 20 C to 60 C Non operating Altitude Operating up to 2 000 metres 6 562 feet Pollution degree Pollution Degree 2 NOTE The Keysight U3401A dual display complies with the following EMC requirements IEC 61010 1 2001 EN61010 1 2001 2nd Edition Canada CAN CSA C22 2 No 61010 1 04 USA ANSI UL 61010 1 2004 I...

Page 7: ...992 ICES NMB 001 indicates that this ISM device complies with the Canadian ICES 001 Cet appareil ISM est conforme a la norme NMB 001 du Canada This instrument complies with the WEEE Directive 2002 96 EC marking requirement This affixed product label indicates that you must not discard this electrical or electronic product in domestic household waste The CSA mark is a registered trademark of the Ca...

Page 8: ... 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 s...

Page 9: ... 18 Checking the shipping contents 19 Connecting power to the instrument 20 Stacking the U3401A 21 Adjusting the Handle 22 Product at a Glance 23 Product dimensions 23 The front panel at a glance 24 The display at a glance 25 The keypad at a glance 28 The terminals at a glance 31 The rear panel at a glance 33 Making measurements 34 Performing voltage measurements 35 Performing current measurements...

Page 10: ...amples 65 Measure DC Voltage and AC Ripple on a Rectification Circuit 65 Measure AC and DC Current on a Rectification Circuit 66 Measure AC Voltage and Frequency on an AC Circuit 67 Measure Resistance 68 Measure True RMS AC DC 69 4 Performance Test Calibration Overview 72 Keysight Technologies calibration services 72 Calibration interval 72 Recommended Test Equipment 73 Test Considerations 74 Perf...

Page 11: ...g for shipment 86 Cleaning 86 To replace the power line fuse 87 To replace a current input fuse 88 Electrostatic Discharge ESD precautions 88 Mechanical Disassembly 89 Replaceable Parts 95 To order replaceable parts 95 6 Characteristics and Specifications ...

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Page 13: ... Figure 1 14 Frequency terminal connection and display 39 Figure 1 15 Resistance continuity terminal connection and display 40 Figure 1 16 Forward biased diode continuity test terminal connection and display 42 Figure 1 17 Reverse biased diode continuity terminal connection and display 42 Figure 2 1 Typical dBm operation display 47 Figure 2 2 Typical Rel operation display 48 Figure 2 3 Typical Max...

Page 14: ... s and Service Guide Figure 3 2 Connection terminal when using DC current and AC ripple 66 Figure 3 3 Connection terminal when measuring AC Voltage and Frequency 67 Figure 3 4 Connection terminal when measuring Resistance 68 ...

Page 15: ...u and communications parameters 59 Table 3 1 Typical combinations and applications when using dual display 64 Table 4 1 Recommended test equipments 73 Table 4 2 DC voltage verification test 76 Table 4 3 DC current verification test 77 Table 4 4 2 wire Ω verification test 78 Table 4 5 Diode verification test 79 Table 4 6 Frequency verification test 79 Table 4 7 AC volts verification test 80 Table 4...

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Page 17: ...ual Display Multimeter 18 Connecting power to the instrument 20 Stacking the U3401A 21 Adjusting the Handle 22 Product at a Glance 23 Making measurements 34 Selecting a Range 43 This chapter provides an introduction to the U3401A digital multimeter and a tutorial showing how to use the front panel in order to make measurements ...

Page 18: ... voltage DC voltage AC current DC current AC DC voltage AC DC current Resistance Frequency Continuity test Diode test Six math operations dBm Min Max Hold Relative Rel Compare Comp Percentage 50 000 count dual display AC and DC current measurements to 10 A Resistance measurement up to 50 MΩ 10 mΩ resolution Frequency measurement up to 500 kHz with 0 01 Hz resolution Measurement of dBm with variabl...

Page 19: ...d materials identical to those used in the factory packaging are available through Keysight Technologies office If the multimeter is being returned to Keysight Technologies for servicing attach a tag indicating the type of service required return address model number and serial number Also mark the container FRAGILE to assure careful handling In any correspondence refer to the multimeter by model ...

Page 20: ...ing enabled If self test is successful the multimeter goes to normal operation If the self test fails either a full annunciator or a blank display is displayed without entering the normal operation If the self test repeatedly fails contact your nearest Keysight Sales and Service Office NOTE The multimeter will operate at any line voltage between 90 VAC and 264 VAC when the line voltage selector is...

Page 21: ...ipped with specially designed anti slip protective bumpers on the front and rear panel The multimeters will not slide off when stacked on top of each other To be able to stack the U3401A multimeters ensure the attached bumpers are in correct orientation See Figure 1 1 Figure 1 1 Stacking the U3401A ...

Page 22: ...tate the handle to the desired position Figure 1 2 below shows the possible handle positions Figure 1 2 Type of handle position To attach or detach the handle rotate the handle upright and pull it out from the sides of the multimeter Refer to Figure 1 3 Figure 1 3 Attaching and detaching the handle Carrying position Handle removal position Benchtop position ...

Page 23: ...Getting Started 1 Keysight U3401A User s and Service Guide 23 Product at a Glance Product dimensions Front view Side view Figure 1 4 U3401A dimensions 226 0 mm 105 0 mm 305 0 mm ...

Page 24: ...ce Guide The front panel at a glance Figure 1 5 Front panel Measurement function keypads Math operation keypads Primary display Secondary display Autoranging manual range and comparator operation Shift Power on off switch Input terminals and current fuse ...

Page 25: ...Slow Not applicable for the U3401A M Reading rate Medium Not applicable for the U3401A F Reading rate Fast Not applicable for the U3401A PEAK Peak measurement Not applicable for the U3401A HOLD Data hold MIN MinMax math operation Minimum value shown on the primary display MAX MinMax math operation Maximum value shown on the primary display REL Relative value dBm Decibel unit relative to 1 mW 4 2 W...

Page 26: ...sistance unit Ω kΩ MΩ MkHz Frequency unit Hz kHz MHz Secondary display Polarity digits and decimal points for secondary display μmnF Capacitance unit μF nF mF C Celcius temperature unit Not applicable for the U3401A F Fahrenheit temperature unit Not applicable for the U3401A Duty cycle measurement mV Voltage unit mV V μmA Current unit μA mA A S Shift mode MkΩ Resistance unit Ω kΩ MΩ 2ND Secondary ...

Page 27: ...alibration mode EXT External Not applicable for the U3401A TRIG Trigger mode REMOTE Remote interface control For calibration use only LOCAL Local mode STO Store instrument state Not applicable for the U3401A RCL Recall stored instrument state Not applicable for the U3401A Table 1 1 Display annunciators continued Annunciator Description ...

Page 28: ...bol on the display and emits a beep Figure 1 7 Keypad Table 1 2 Keypad functions Key Description System related operation Press to power on or power off the U3401A multimeter Press to select Shift Press to return the multimeter to front panel operation when it is in remote state Press to step through the Setup menu See Using the setup menu on page 59 for more information Press to enable the second...

Page 29: ...oltage measurement Press to select AC DC current measurement Press to select the frequency measurement Press to toggle between the diode and continuity measurement Press to toggle between resistance or resistance continuity Press to select dBm measurement Press to select the reference impedance for dBm measurement Press to toggle between manual ranging and autoranging Press to select a higher rang...

Page 30: ...t Compare math operation Press to select and set the high limit for Compare math operation Press to select and set the low limit for Compare math operation Press to enable Hold math operation See Hold on page 53 on for more information Press to enable the MinMax math operation Press to select the Relative math operation Press to select the Percentage operation Table 1 2 Keypad functions continued ...

Page 31: ...limit NOTE Voltages above 300 VAC may be measured only in circuits that are isolated from mains However transient overvoltages are also present on circuits that are isolated from mains The Keysight U3401A is designed to safely withstand occasional transient overvoltages up to 2500 V PEAK Do not use this multimeter to measure circuits where transient overvoltages could exceed this level ...

Page 32: ...COM 1000 VDC AC voltage VAC frequency Hz 750 VAC RMS 1100 V PEAK 2x107 V Hz normal mode or 1x106 V Hz common mode Miliampere mA frequency Hz mA 500 mADC or AC RMS 10 A frequency Hz 10 A 10 ADC or AC RMS continuous and 10 A DC RMS for 20 seconds maximum Resistance Ω 500 VDC or AC RMS Diode test continuity test 500 VDC or AC RMS All functions Any terminal to earth 1000 VDC or AC PEAK ...

Page 33: ...ser s and Service Guide 33 The rear panel at a glance Figure 1 9 Rear panel AC line voltage selector Line voltage fuse selection table AC power connector AC line fuse Chassis ground lug RS232 interface connector For calibration use only ...

Page 34: ...00 VDC you are recommended to wait for approximate two minutes before measuring a low level measurement with 1 to 10 μV resolutions After measuring a high current measurement using the A input terminal you are recommended to wait for approximate ten minutes before measuring a low level DC measurements of volts amperes or ohms to achieve accurate measurement This is due to the thermal voltages gene...

Page 35: ...ck test leads to the respective input terminals as shown in Figure 1 10 3 Probe the test points and read the display In autoranging mode the multimeter automatically selects the appropriate range and the measurement is displayed Figure 1 10 ACV terminal connection and display WARNING Exceeding the crest factor limit may result in an incorrect or a lower reading Do not exceed the crest factor limit...

Page 36: ...ce 10 MΩ 2 range typical Input protection 1000 V on all ranges 1 Press 2 Connect the red and black test leads to the respective input terminals as shown in Figure 1 11 3 Probe the test points and read the display In autoranging mode the multimeter automatically selects the appropriate range and the measurement is displayed Figure 1 11 DCV terminal connection and display DCV voltage source ...

Page 37: ... 100 Ω for 500 μA to 10 A ranges Input protection Internal 25 A 440 V FH fuse for one terminal 1 Press or 2 Power off the measured circuit 3 Connect the red and black test leads to mA input terminal as shown in Figure 1 12 4 Probe the test points in series with the circuit 5 Power on the measured circuit and read the display Figure 1 12 ACI RMS or DCI mA terminal connection and display ACI or DCI ...

Page 38: ...r 500 μA to 10 A ranges Input protection Internal 25 A 440 V fuse for 10A terminal 1 Press or 2 Press or to select the measurement range 3 Power off the measured circuit 4 Connect the red and black test leads to the A input terminal as shown in Figure 1 13 5 Probe the test points in series with the circuit 6 Power on the measured circuit and read the display Figure 1 13 ACI RMS or DCI 10A terminal...

Page 39: ...all ranges Gate time 0 1 s or 1 period of the input signal whichever is longer Input protection 1000 V RMS on all ranges 1 Press 2 Connect the red and black test leads to the input terminal as shown in Figure 1 14 3 Probe the test points and read the display In autoranging mode the multimeter automatically selects the appropriate range and the measurement is displayed Figure 1 14 Frequency termina...

Page 40: ... test leads to the input terminal as shown in Figure 1 15 3 Probe the test points by shunting the resistor and read the display In autoranging mode the multimeter automatically selects the appropriate range and the measurement is displayed Figure 1 15 Resistance continuity terminal connection and display CAUTION Disconnect circuit power and discharge all high voltage capacitors before measuring re...

Page 41: ... the circuit Then proceed as follows 1 Press to toggle the diode and continuity function The default function is diode measurement 2 Connect the red and black test leads to the input terminal as shown in Figure 1 16 on page 42 3 Connect the red test lead to the positive terminal anode of the diode and the black test lead to the negative terminal cathode Refer to Figure 1 16 on page 42 4 Read the d...

Page 42: ...everse bias modes and the multimeter beeps continuously A diode is considered open if the multimeter displays OL in both forward and reverse bias modes Figure 1 16 Forward biased diode continuity test terminal connection and display Figure 1 17 Reverse biased diode continuity terminal connection and display Test current Forward bias Reverse bias Test current ...

Page 43: ...or both the primary and secondary display are corresponding to the higher range of two displays Manual ranging If the input signal is greater than can be measured on the selected range the multimeter will display an overload indication OL on the primary or secondary display front panel The multimeter remembers the selected ranging method auto or manual and the selected manual range for each measur...

Page 44: ...50 000 V DCI ACI DCI ACI 500 000 μA 5 000 mA 50 000 mA 500 000 mA DCI ACI DCI ACI 5 000 A 10 000 A a Frequency 500 000 Hz 5 000 kHz 500 000 kHz 500 000 kHz Resistance 500 000 Ω 5 000 kΩ 50 000 kΩ 500 000 kΩ 5 000 MΩ 50 000 MΩ Diode test 2 3000 V Fixed range Continuity 500 000 5 000 k 50 000 k 500 000 k 5 000 M 50 000 MΩ Continuity Mode Notes a You are required to select the range manually when a s...

Page 45: ...Display Multimeter User s and Service Guide 45 2 Operations and Features Operating Math Functions 46 Using the Secondary Display 57 This chapter explains the various functions and features available on the U3401A digital multimeter ...

Page 46: ...an be turned on at a time When selecting another math operation when one is already on you are required to turn off the first operation and then turn on the second math operation All math operations are automatically turned off when changing the measurement functions Range changing is allowed for all math operations Table 2 1 Math operations for different measurement functions Measurement function...

Page 47: ...mpedance Figure 2 1 Typical dBm operation display The default reference impedance value is 600 Ω You can select the following 21 reference impedance values 2 Ω 4 Ω 8 Ω 16 Ω 50 Ω 75 Ω 93 Ω 110 Ω 124 Ω 125 Ω 135 Ω 150 Ω 250 Ω 300 Ω 500 Ω 600 Ω 800 Ω 900 Ω 1000 Ω 1200 Ω 8000 Ω The dBm operation can be applied to DCV ACV and DCV ACV measurement functions only The multimeter displays the dBm modifier o...

Page 48: ...rate resistance measurements by nulling the test lead resistance After you enable the Rel operation the multimeter stores the next reading as a Rel reference value and immediately displays on the primary display Primary Display Reading Rel When the Rel operation is enabled in autoranging mode enabling the Comp or Percentage operation will disable the Rel operation Procedure 1 Press to exit the rel...

Page 49: ...accumulating various statistics of the readings being displayed Figure 2 3 Typical Max operation display Figure 2 4 Typical Min operation display Each time a new minimum or maximum value is stored the multimeter beeps once if the beeper is enabled and briefly turns on the appropriate MAX or MIN annunciator Accumulated statistics are MAX maximum reading since MinMax was enabled MIN minimum reading ...

Page 50: ...ime is shown on the secondary display with HH MM SS HH is 0 19 hours MM is 0 59 minutes SS is 0 59 seconds Procedure 1 Press to enable MinMax operation 2 Press continuously until the desired operation appear The MinMax operation will display MINMAX MAX MIN MINMAX in sequence when this key is press continuously 3 Press to disable the MinMax operation ...

Page 51: ... results such as HI LO or PASS is shown in secondary display You should specify the upper limit to always be a more positive number than the lower limit The initial factory setting for each limit is 0 The secondary display shows PASS when readings are within the specified limits The secondary display shows HI when the reading is outside the high limit and LO when the reading is outside the low lim...

Page 52: ...lay while the HI annunciator is shown on secondary display 2 Use and to modify the upper limit 3 Press to store the specified HI limit value 4 Press to enter the lower limit setup mode The lower limit is shown on primary display while the LO annunciator is shown on secondary display 5 Use and to modify the lower limit 6 Press to store the specified LO limit value ...

Page 53: ...e reading on the display Figure 2 6 Typical Hold operation display Refresh Hold The refresh hold operation allows you to take measurement in dangerous or difficult measuring field and you could not look at the display This operation will update the hold value with a new measurement value automatically and thus reminds you with a beep Procedure 1 Press to access to the Setup menu 2 Use and to selec...

Page 54: ...ion of measuring value exceeds the setting of the variation count The HOLD annunciator will be blinking continuously 7 When the refresh hold is not in use repeat step 1 to step 4 to turn off the refresh hold s state Figure 2 7 Typical refresh hold operation display NOTE For voltage and current measurements the held value will not be updated when the reading is below 500 counts For resistance and d...

Page 55: ...he measurement value using the equation below Percentage Measurement value LO HI LO x 100 When the HI limit is equal to LO limit the percentage operation will use the equation as below Percentage Measurement value HI HI x 100 Figure 2 8 Typical percentage operation display When enabled the actual readings are shown in primary display and the percentage s result is shown in secondary display The se...

Page 56: ...n secondary display 2 Use and to modify the upper limit 3 Press to store the specified HI limit value 4 Press to enter the lower limit setup mode The lower limit is shown on primary display while the LO annunciator is shown on secondary display 5 Use and to modify the lower limit 6 Press to store the specified LO limit value 7 Press to enable percentage operation 8 Press to disable percentage oper...

Page 57: ...gure 2 9 Secondary display To enable the secondary display mode Repeatedly pressing cycles through the secondary display choices for the present math operation as shown in Table 2 2 on page 58 To disable the secondary display mode Press The display will remain in primary display mode Secondary display ...

Page 58: ...ency a ACV ACI COMP Measuring Value HI LO PASS Percentage Measuring Value Notes a The Frequency reading is corresponding to the current or voltage input signal respectively The Frequency measurement is always working on autoranging mode The Buttons of AUTO UP and DOWN are used to select the range of measuring signal If the current measurement is set before selecting Hz function the default will sh...

Page 59: ...tA Data bit length for remote communication with a PC 8 7 or 8 StoP Stop bit 1 1 or 2 Echo ECHO Return a character to PC in remote communication OFF ON or OFF Print Printer Only Print measured data to a PC in remote communication OFF ON or OFF Ref Ω Reference impedance 600 Ω 8000 Ω 1200 Ω 1000 Ω 900 Ω 800 Ω 600 Ω 500 Ω 300 Ω 250 Ω 150 Ω 135 Ω 125 Ω 124 Ω 110 Ω 93 Ω 75 Ω 50 Ω 16 Ω 8 Ω 4 Ω 2 Ω bEEP ...

Page 60: ...desired configurable items in the first tier menu 3 Press to enter second tier menu The original parameter is indicated in primary display 4 Use or to select the desired parameter 5 Press to confirm the selected parameter or press to quit from the tier menu without saving the changes 6 After saving the changes press to quit from the tier menu 7 Press again to quit from the setup menu 8 The configu...

Page 61: ...nabled the multimeter determines the range for the primary display based on the input at that time Autoranging response time is required before a reading is displayed when you change the input after a trigger is received Procedure 1 Press to enter trigger mode and standby condition The TRIG annunciator will be lit and display is indicated with 2 Press to get a new value After a measurement the res...

Page 62: ...ser s and Service Guide NOTE All math operations will be disabled when external trigger is enabled Press may also disable external trigger Both the primary and secondary display will only appear when frequency operation is selected in trigger mode ...

Page 63: ...ter User s and Service Guide 63 3 Application Tutorial Applications for Using Dual Display 64 Dual Display Operation Examples 65 This chapter describes the advanced features and the possible applications for effective operation of the multimeter ...

Page 64: ...splay No Primary display Secondary display Applications 1 DCV ACV Test DC to AC or AC to DC converter circuit Measure DC level and AC ripple of power supply 2 ACV DCV DCV 3 ACV Frequency Measuring AC frequency response of amplifier circuit Adjusting AC motor control 4 ACI Frequency 5 DCI ACI Measuring AC ripple and DC current of power supply Measuring current dissipation for power supply analysis ...

Page 65: ...ectifier circuit 1 Connect the red and black test leads to the input terminal and probe the test points as shown in Figure 3 1 Figure 3 1 Connection terminal when measuring DC voltage and AC ripple 2 Press to select DC voltage measurement in primary display 3 Press to select AC voltage measurement for secondary display 4 Press Use and to select autoranging or manual range for secondary display NOT...

Page 66: ...t points as shown in Figure 3 2 Figure 3 2 Connection terminal when using DC current and AC ripple 2 Press to select AC current measurement for primary display 3 Press to enable the DC current measurement for secondary display 4 Press or to select autoranging or manual range for secondary display WARNING Make sure you select the correct input terminal according to the input range used Do not apply...

Page 67: ...cuit 1 Connect the red and black test leads to the input terminal and probe the test points as shown in Figure 3 3 Figure 3 3 Connection terminal when measuring AC Voltage and Frequency 2 Press to select AC voltage measurement for primary display 3 Press to select frequency measurement for secondary display 4 Press or to select autoranging or manual range for secondary display NOTE Press to disabl...

Page 68: ...st to and LO input terminals as shown in Figure 3 4 Figure 3 4 Connection terminal when measuring Resistance 2 Press to select resistance measurement 3 Press Use and to select autoranging or manual range for primary display WARNING Do not apply voltage exceeding 500 V PEAK between and COM input terminals Resistance ...

Page 69: ...f AC voltage and AC current 1 Press and or and simultaneously The multimeter will measure the DC and AC signals alternatively calculate and display the AC DC RMS value using the quation below AC DC RMS DC2 AC2 NOTE When AC DC voltage measurement is selected the DCV input impedance is paralleled with the AC coupled 1 1 MΩ AC divider ...

Page 70: ...3 Application Tutorial 70 Keysight U3401A User s and Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 71: ...res The performance tests procedures allow you to verify that the multimeter is operating within its published specifications WARNING Shock hazard Only service trained personnel who are aware of the hazards involved should perform the procedures in this chapter To avoid electrical shock and personal injury make sure to read and follow all test equipment safety instructions Use only completely elec...

Page 72: ...tion interval A one year interval is adequate for most applications Accuracy specifications are warranted only if adjustment is made at regular calibration intervals Accuracy specifications are not warranted beyond the one year calibration interval Keysight does not recommend extending calibration intervals beyond two years for any application When an adjustment is required contact your local Keys...

Page 73: ...asured from the source can be entered into the instrument as the target calibration value Table 4 1 Recommended test equipments Application Recommended equipment Recommended accuracy requirements Zero calibration Shorting plug Dual banana plug with copper wire short between the two terminals DC voltage Fluke 5520A 1 5 instrument 1 year spec DC current Fluke 5520A 1 5 instrument 1 year spec Resista...

Page 74: ...elded twisted pair PTFE insulated cables to reduce settling and noise errors Keep the input cables as short as possible Connect the input cable shields to earth ground Connect the calibrator Lo source to earth ground at the calibrator except where noted in the procedures It is important that the Lo to earth ground connection be made at only one place in the circuit to avoid ground loops NOTE Pleas...

Page 75: ... against the one year test limits After acceptance you should repeat the performance verification tests at every calibration interval If the instrument fails performance verification adjustment or repair is required Contact your local Keysight Service Center for details This test checks the full scale reading accuracy of the instrument DC Voltage Verification Test 1 Connect the calibrator to the f...

Page 76: ...ts to the appropriate test limits shown in Table 4 3 Be certain to allow for appropriate source settling when using the Fluke 5520A Table 4 2 DC voltage verification test Function Input Range Error from nominal one year DC voltage 0 00 V 500 mV 40 μV 0 0000 V 5 V 0 4 mV 0 000 V 50 V 4 mV 0 00 V 500 V 40 mV 0 0 V 1000 V 400 mV 450 00 mV 500 mV 130 μV 4 5000 V 5 V 1 3 mV 45 000 V 50 V 13 mV 450 00 V...

Page 77: ... DC current 0 00 μA 500 μA 0 05 μA 0 0000 mA 5 mA 0 4 μA 0 000 mA 50 mA 4 μA 0 00 mA 500 mA 40 μA 450 00 μA 500 μA 0 27 μA 4 5000 mA 5 mA 2 6 μA 45 000 mA 50 mA 26 μA 450 00 mA 500 mA 0 26 mA 0 0000 A 5 A 0 5 mA 0 000 A 10 A 5 mA 4 5000 A 5 A 11 7 mA 9 000 A 10 A 27 mA CAUTION Connect calibrator to multimeter s A and Lo terminals before applying 10 A ...

Page 78: ...Be certain to allow for appropriate source settling Table 4 4 2 wire Ω verification test Function Input Range Error from nominal one year 2 wire Ω 0 00 Ω 500 Ω 50 mΩ a 0 0000 kΩ 5 kΩ 0 3 Ω a 0 000 kΩ 50 kΩ 3 Ω 0 00 kΩ 500 kΩ 30 Ω 0 0000 MΩ 5 MΩ 300 Ω 0 000 MΩ 50 MΩ 3 kΩ 450 00 Ω 500 Ω 500 mΩ a 4 5000 kΩ 5 kΩ 4 8 Ω a 45 000 kΩ 50 kΩ 48 Ω 450 00 kΩ 500 kΩ 480 Ω 4 5000 MΩ 5 MΩ 4 8 kΩ 30 000 MΩ 50 MΩ ...

Page 79: ...ate source settling when using the Fluke 5520A Frequency Verification Test Configuration Frequency 1 Select the frequency function 2 Select each range in the order shown in Table 4 6 Provide the input voltage and frequency indicated Compare measurement results to the appropriate test limits shown in Table 4 6 Be certain to allow for appropriate source settling Table 4 5 Diode verification test Fun...

Page 80: ...certain to allow for appropriate source settling Table 4 7 AC volts verification test Function V RMS Input frequency Range Error from nominal one year AC voltage 50 00 mV 1 kHz 500 mV 650 μV 450 00 mV 1 kHz 500 mV 2 65 mV 0 5000 V 1 kHz 5 V 3 2 mV 4 5000 V 1 kHz 5 V 17 2 mV 5 000 V 1 kHz 50 V 32 mV 45 000 V 1 kHz 50 V 172 mV 50 00 V 1 kHz 500 V 400 mV 450 00 V 1 kHz 500 V 2 4 V 75 0 V 1 kHz 750 V ...

Page 81: ...n Table 4 8 Be certain to allow for appropriate source settling Table 4 8 AC current verification test Function Current Input frequency Range Error from nominal one year AC current 50 00 μA 1 kHz 500 μA 0 45 μA 450 00 μA 1 kHz 500 μA 2 45 μA 0 5000 mA 1 kHz 5 mA 4 5 μA 4 5000 mA 1 kHz 5 mA 24 5 μA 5 000 mA 1 kHz 50 mA 45 μA 45 000 mA 1 kHz 50 mA 0 245 mA 50 00 mA 1 kHz 500 mA 0 45 mA 450 00 mA 1 k...

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Page 83: ...embly and Repair Operating Checklist 84 Types of Service Available 85 Mechanical Disassembly 89 Replaceable Parts 95 This chapter will help you troubleshoot a faulty multimeter It describes how to disassemble the multimeter how to obtain repair services and lists the replaceable parts ...

Page 84: ...or repair check the following items Is the multimeter inoperative Verify the power line voltage setting Verify the power line fuse is installed Check the power cord is connected to multimeter and to AC line power Verify the front panel power switch is depressed See page 86 Is the mutimeter s current input inoperative Verify the current input fuse ...

Page 85: ...btain service for your instrument in warranty under service contract or post warranty contact your nearest Keysight Technologies Service Center They will arrange to have your instrument repaired or replaced and can provide warranty or repair cost information where applicable To obtain warranty service or technical support information you can contact Keysight Technologies at one of the following te...

Page 86: ...kaging material for shipping Secure the container with strong tape or metal bands If the original shipping container is not available place your instrument in a container which will ensure at least 4 inches of compressible packaging material around all sides for the instrument Use static free packaging materials to avoid additional damage to your instrument Keysight suggests that you always insure...

Page 87: ...f the same size and rating Table 5 1 Type of supplied fuse according to country of destination Type of fuse time lag low breaking fuse Input line voltage Part number 0 25A 250V 5x20 mm 100 V to 120 V A02 62 25592 3U 0 125A 250V 5x20 mm 220 V to 240 V A02 62 25648 1U 2 Remove the line voltage selector from fuse holder assembly 1 Disconnect the power cord Depress tab 1 and 2 and pull the fuse holder...

Page 88: ...ize and rating Electrostatic Discharge ESD precautions Almost all electrical components can be damaged by electrostatic discharge ESD during handling Component damage can occur at electrostatic discharge voltages as low as 50 volts The following guidelines will help prevent ESD damage when servicing the instrument or any electronic device Disassemble instruments only in a static free work area Use...

Page 89: ...all cables from the instrument 2 Remove the carrying handle by rotating the handle upright and pulling out from the sides of the instrument WARNING Shock hazard Only service trained personnel who are aware of the hazards involved should remove the instrument covers To avoid electrical shock and personal injury make sure to disconnect the power cord from the instrument before removing the covers So...

Page 90: ...eysight U3401A User s and Service Guide 3 Remove the instrument bumpers Pull from a corner and stretch the bumpers off the instrument 4 Remove the rear bezel Loosen the two captive screws in the rear bezel and remove the rear bezel ...

Page 91: ...er Remove the screw in the bottom of the cover and slide the cover off the instrument Front Panel Removal 1 Remove on off switch push rod Gently move the power switch push rod toward the front of the instrument to disengage it from the switch Be careful not to twist or bend the push rod ...

Page 92: ...5 Disassembly and Repair 92 Keysight U3401A User s and Service Guide 2 Remove the screw holding the front panel 3 Disconnect the two ribbon cable connectors from the front panel ...

Page 93: ...ht U3401A User s and Service Guide 93 4 Disconnect the individual front panel wires shown below 5 There is now enough play to allow the side of the front panel to be pried from the chassis and removed as an assembly 25 A current fuse ...

Page 94: ... Service Guide Front Panel Disassembly 1 Remove the keyboard and display assembly Remove the two screws holding the circuit board Lift the keyboard and display assembly from the plastic housing a The rubber keypad can now be pulled from the plastic housing ...

Page 95: ...t includes a brief description of each part with applicable Keysight part number To order replaceable parts You can order replaceable parts from Keysight using the Keysight part number Note that not all parts listed are available as field replaceable parts To order replaceable parts from Keysight do the following 1 Contact your nearest Keysight Sales Office or Service Center 2 Identify the parts b...

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Page 97: ...eter User s and Service Guide 97 6 Characteristics and Specifications For the characteristics and specifications of the U3401A 4 Digit Dual Display Multimeter refer to the datasheet at http literature cdn keysight com litweb pdf 5990 3970EN pdf ...

Page 98: ...6 Characteristics and Specifications 98 Keysight U3401A User s and Service Guide THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK ...

Page 99: ... is subject to change without notice Always refer to the Keysight website for the latest revision Keysight Technologies 2009 2017 Edition 14 November 1 2017 Printed in Malaysia U3401 90001 U3401 90001 www keysight com ...

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