SIGLENT TECHNOLOGIES SDM3045X User manual

SDM3045X Service Manual I
SDM3045X
Digital Multimeter
Service Manual
SM06034-E02C

Guaranty and Declaration
Copyright
SIGLENT TECHNOLOGIES CO., LTD All Rights Reserved.
Trademark Information
SIGLENT is the registered trademark of SIGLENT TECHNOLOGIES CO.,
LTD
Declaration
⚫SIGLENT products are protected by patent law in and outside of the P.R.C.
⚫SIGLENT reserves the right to modify or change parts of or all the
specifications or pricing policies at company’s sole decision.
⚫Information in this publication replaces all previously corresponding
material.
⚫Any way of copying, extracting or translating the contents of this manual is
not allowed without the permission of SIGLENT.
⚫SIGLENT will not be responsible for losses caused by either incidental or
consequential in connection with the furnishing, use or performance of this
manual as well as any information contained.
Product Certification
SIGLENT guarantees this product conforms to the national and industrial
standards in China as well as the ISO9001: 2015 standard and the ISO14001:
2015 standard. Other international standard conformance certification is in
progress.

SDM3045X Service Manual III
General Safety Summary
Review the following safety precautions to avoid personal injury and to prevent
damage to this product or any products connected to it. To avoid potential
hazards, use this product only as specified.
Only qualified personnel should perform service procedures.
To Avoid Fire or Personal Injuries
Use Proper Power Cord. Use only the power cord specified for this product
and approved by the local regulating body.
Avoid Electric Shock. To avoid injuries or losses of life, do not connect or
disconnect probes or test leads while they are connected to a voltage source.
Ground the Product. This product is grounded through the protective terra
conductor of the power line. To avoid electric shock, the grounding conductor
must be connected to the earth. Make sure the instrument is grounded
correctly before connecting its input or output terminals.
Connect the Probe Properly. Do not connect the probe ground lead to a high
voltage since it has the isobaric electric potential as ground.
Observe All Terminal Ratings. To avoid fire or shock hazard, observe all
ratings and markers on the instrument and check your manual for more
information about ratings before connecting.
Use Proper Fuse. Use only the specified fuse.
Do Not Operate Without Covers. Do not operate this instrument with covers
or panels removed.

Avoid Circuit or Wire Exposed. Do not touch exposed junctions and
components when the unit is powered.
Do Not Operate With Suspected Failures. If you suspect damage has
occurred to this instrument, have it inspected by qualified service personnel
before any further operation. Any maintenance, adjustment or replacement
especially to the circuits or accessories should be performed by SIGLENT
authorized personnel only.
Keep Product Surfaces Clean and Dry.
Do Not Operate in Wet/Damp Conditions. To avoid electric shock, do not
operate the instrument in wet or damp conditions.
Do Not Operate in an Explosive Atmosphere. To avoid injuries or fire
hazards, do not operate in an explosive atmosphere.
Safety Terms and Symbols
Terms on the Product. These terms may appear on the product:
DANGER: Indicates an injury or hazard that may immediately happen.
WARNING: Indicates that there is potential for an injury or hazard.
CAUTION: Indicates damage to the instrument or other property may occur.
Symbols on the Product. These symbols may appear on the product:

SDM3045X Service Manual V
Catalog
General Safety Summary.............................................................................................................III
General Features and Specifications..........................................................................................1
General Features....................................................................................................................1
Specifications..........................................................................................................................2
Prepare Information.......................................................................................................................6
Functional check.....................................................................................................................6
Power-on Inspection......................................................................................................6
Default Setup ..................................................................................................................6
Self Test ...........................................................................................................................7
Performance Verification...............................................................................................................8
Performance verification test items .....................................................................................8
Recommended Test Equipment...........................................................................................8
Performance verification step...............................................................................................8
Test Considerations................................................................................................................9
Zero Offset Verification..........................................................................................................9
DC Voltage and DC Current Gain Verification.................................................................10
Frequency Accuracy Verification........................................................................................11
AC Voltage and AC Current Verification............................................................................11
Capacitance Verification......................................................................................................12
Assembly Procedures..................................................................................................................13
Security Consideration ........................................................................................................13
Required Tools......................................................................................................................13
Disassembly Procedures ....................................................................................................14
Troubleshooting............................................................................................................................18
ESD Precautions..................................................................................................................18
Required Equipments..........................................................................................................18
Analog Board Drawing.........................................................................................................19
Main Board Drawing ............................................................................................................20
Check the Power Supply.....................................................................................................21
Check the Analog Board......................................................................................................22
Voltage Check...............................................................................................................22
Analog board Clock Check .........................................................................................23
Check the Main Board.........................................................................................................23
Voltage Check...............................................................................................................23
Microprocessor Check.................................................................................................24
Quick Guide for General Failures......................................................................................24
Maintenance..................................................................................................................................25
Maintenance Summary........................................................................................................25
Repackaging for Shipment..................................................................................................25

SDM3045X Service Manual 1
General Features and Specifications
The SDM3045X is a multimeter with 4½ digit reading resolution and
dual-display suited for any application requiring high-precision, multifunction,
and automated measurements. It features a combination of basic
measurement, multiple math, and display functions, etc.
General Features
⚫Real 4½ digit reading resolution
⚫Up to 150 rdgs/S measurement speed
⚫True-RMS AC Voltage and AC Current measurements
⚫1 Gb Nand Flash size, mass storage configuration files and data files
⚫Built-in cold terminal compensation for accurate thermocouple readings
⚫Includes EasyDMM PC software for easy control and data collection
⚫Built-in help system, convenient to acquire information
⚫Standard communication interfaces: USB Device, USB Host, LAN
(Optional : USB-GPIB Adapter)
⚫USB & LAN remote interfaces support common SCPI commands.
Compatible with other popular DMMs on the market

Specifications
DC Characteristics
Accuracy±（% of Reading + count）[1]
Function
Range[2]
Test current or
Load voltage
Resolution
Accuracy
（one year；
23℃±5℃）
DC Voltage
600 mV
0.01 mV
0.02+ 6
6V
0.0001 V
0.02+ 6
60 V
0.001 V
0.02+ 6
600 V
0.01 V
0.02+ 6
1000 V[4]
0.1 V
0.02+ 6
DC Current
600 μA
< 33 mV
0.01 μA
0.05+ 3
6 mA
< 330 mV
0.0001 mA
0.05+ 3
60 mA
< 0.05 V
0.001 mA
0.05+ 3
600 mA
< 0.5 V
0.01 mA
0.12+ 6
6 A
< 0.33 V
0.0001 A
0.20+ 5
10 A[5]
< 0.6 V
0.001 A
0.25+ 4
Resistance[3]
600 Ω
1 mA
0.01 Ω
0.08+ 6
6 kΩ
1 00 μA
0.0001 kΩ
0.04+ 6
60 kΩ
10 μA
0.001 kΩ
0.04+ 6
600 kΩ
1 μA
0.01 kΩ
0.08+ 6
6 MΩ
200 nA
0.0001 MΩ
0.12+ 3
60 MΩ
200 nA || 10 MΩ
0.001 MΩ
0.85+ 3
100 MΩ
200 nA || 10 MΩ
0.01 MΩ
1.75+ 3
Diode Test[6]
0～2V
1 mA
0.0001 V
0.05+ 3
2～4V
1 mA
0.0001 V
0.35+ 3
Continuity Test
2000 Ω
1 mA
0.1 Ω
0.05+ 3
Remarks:
[1] Specifications are for 0.5 Hour warm-up, “Slow”measurement rate and calibration
temperature 18℃～28℃.
[2]10% over range on all ranges except for DCV 1000 V, ACV 750 V, DCI 10 A and ACI 10
A.
[3] Specifications are for 4-wire measure or 2-wire measure under “REF”operation.±0.2Ω
of extra errors will be generated if perform 2-wire measure without “REF”operation.
[4] Plus 0.02 mV of error per 1 V after the first ±500 VDC.
[5] 30 seconds OFF after 30 seconds ON is recommend foe the continuous current that
higher than DC 7 A or AC RMS 7 A.
[6] Accuracy specifications are only for voltage measuring at input terminal. The typical
value of current under measure is 1 mA. Voltage drop at diode junction may vary with
current supply. Adjustable voltage range ：0~4 V.

SDM3045X Service Manual 3
AC Characteristics
Accuracy ±（% of Reading + count）[1]
Function
Range[2]
Frequency
Range
Resolution
Accuracy
（one year；
23℃±5℃）
True-RMS
AC Voltage [3]
600 mV
20 Hz –45 Hz
0.01 mV
2.0 + 20
45Hz –100 Hz
0.01 mV
0.6 +10
100 Hz –20 kHz
0.01 mV
0.3 + 20
20 kHz –50 kHz
0.01 mV
2.0 + 40
50kHz –100 kHz
0.01 mV
3.0 + 10
6V
20 Hz –45 Hz
0.0001 V
2.0 + 20
45Hz –100Hz
0.0001 V
0.6 + 10
100 Hz –20 kHz
0.0001 V
0.8 + 20
20 kHz –50 kHz
0.0001 V
2.0 + 40
50 kHz –100 kHz
0.0001 V
3.0 + 40
60 V
20 Hz –45 Hz
0.001 V
2.0 + 20
45 Hz –100 Hz
0.001 V
0.6 +10
100 Hz –20 kHz
0.001 V
0.8 + 20
20 kHz –50 kHz
0.001 V
2.0 + 40
50 kHz –100 kHz
0.001 V
3.0 + 40
600 V
20 Hz –45 Hz
0.01 V
2.0 + 20
45 Hz –100 Hz
0.01 V
0.6 + 10
100 Hz –20 kHz
0.01 V
0.8 + 20
20 kHz –50 kHz
0.01 V
2.0 + 40
50 kHz –100 kHz
0.01 V
3.0 + 40
750 V
20 Hz –45 Hz
0.01 V
2.0 + 20
45 Hz –100 Hz[4]
0.01 V
0.6 + 10
100 Hz –20 kHz
0.01 V
0.8 + 20
20 kHz –50 kHz
0.01 V
2.0 + 40
50 kHz –100 kHz
0.01 V
3.0 + 40
True-RMS
AC Current [5]
60 mA
20 Hz –45 Hz
0.001 mA
2.0 + 20
45 Hz –2 kHz
0.001 mA
0.5 + 20
2 kHz –10 kHz
0.001 mA
2.5 + 30
600 mA
20 Hz –45 Hz
0.01 mA
2.0 + 20
45 Hz –2 kHz
0.01 mA
0.5 + 20
2 kHz –10 kHz
0.01 mA
2.5 + 30
6 A
20 Hz –45 Hz
0.0001A
2.0 + 20
45 Hz –2 kHz
0.0001A
0.5 + 20
2 kHz –10 kHz
0.0001A
2.5 + 20
10 A[6]
20 Hz –45 Hz
0.001 A
1.5 + 45
45 Hz –2 kHz
0.001 A
0.5 + 35

2 kHz –10 kHz
0.001 A
2.5 + 25
Additional wave crest factor error ( not Sine ) [7]
Wave crest coefficient
Error（% Range）
1-2
0.05
2-3
0.3
Remarks:
[1] Specifications are for 0.5 Hour warm-up, “Slow”measurement rate and calibration
temperature 18℃~28℃.
[2] 10% over range on all ranges except for DCV 1000 V, ACV 750 V, DCI 10 A and ACI
10 A.
[3] Specifications are for amplitude of sine wave input > 5% of range. For inputs from 1%
to 5% of range and < 50 kHz, add 0.1% of range extra error. For 50 kHz to 100 kHz,
add 0.1% of range extra error.
[4] Plus 0.025 V of error per 1 V after the first ±400 VAC.
[5] Specifications are for sine wave input > 5% of range. 0.1% errors will be added when
the range of input sine wave is 1% to 5%.
[6] 30 seconds OFF after 30 seconds ON is recommend foe the continuous current that
higher than DC 7 A or AC RMS 7 A.
[7] For inputs Frequency Range < 100Hz
Frequency and Period Characteristics
Accuracy ±（% of Reading + count）[1]
Function
Range
Frequency
Range
Resolution
Accuracy
（one year；
23℃±5 ℃）
Frequency
/Period
600 mV 至750 V[2]
20 Hz –2 kHz
0.01+3
2 kHz –20 kHz
0.01+2
20 kHz –200 kHz
0.01+2
200 kHz–500 kHz
0.01+2
Remarks:
[1] Specifications are for 0.5 Hour warm-up.
[2] Except for special marks, the AC input voltage is 5% to 110% of range when <100 kHz
and 10% to 110% of range when >100 kHz. 750 V range is limited to 750 Vrms.
The accuracy is 10 times % of Reading when the measurement range of AC voltage is
in 600mV range.

SDM3045X Service Manual 5
Capacitance Characteristic
Accuracy±（% of Reading +count）[1]
Function
Range[2]
Max
Testing
Current
Resolution
Accuracy
（one year；
23℃±5 ℃）
Capacitance
2 nF
10 μA
0.001 nF
3+10
20 nF
10 μA
0.01 nF
1+10
200 nF
100 μA
0.1 nF
1+ 9
2 μF
100 μA
0.001 μF
1+10
20 μF
1 mA
0.01 μF
1+10
200 μF
1 mA
0.1 μF
1+ 9
10000 μF
1 mA
1 μF
2+50
Remarks:
[1] Specifications are for 0.5 Hour warm-up and “REF”operation. Using of non-film
capacitor may generate additional errors.
[2] Specifications are for from 1% to 110% on 2 nF range and ranges from 10% to 110%
on other ranges.
Temperature Characteristics
Accuracy ±（% of Reading）[1]
Function
Probe
Type
Probe
Model
Working
Temperature
Range
Accuracy
（one year；
23℃±5℃）
Temperature
coefficient
0℃～18℃
28℃～50℃
Temperature
RTD[2]
α=0.00385
-200℃~660℃
0.16℃
0.09℃
TC[3]
B
20℃~1820℃
0.76℃
0.14℃
E
-270℃~1000℃
0.5℃
0.02℃
J
-210℃~1200℃
0.5℃
0.02℃
K
-270℃~1370℃
0.5℃
0.03℃
N
-270℃~1300℃
0.5℃
0.04℃
R
-50℃~1760℃
0.5℃
0.09℃
S
-50℃~1760℃
0.6℃
0.11℃
T
-270℃~400℃
0.5℃
0.03℃
Remarks:
[1] Specifications are for 0.5 Hour warm-up, not include probe error.
[2] Specifications are for 4-wire measure or 2-wire measure under “REF”operation.
[3] Built-in cold terminal compensation for thermocouple, accuracy is ±2℃.

Prepare Information
Before doing performance verifying or procedure adjusting, you should master
the following operations to make the multimeter work in a good state or deal
with some simple functional problems. The following contents are included in
this chapter:
⚫How to perform functional checks
⚫How to use self-test routine
⚫How to recall factory Default settings
For more detailed information about multimeter operation, please refer to the
User Guide for the SDM3045X.
Functional check
This functional check covers three areas by which you can verify if the
multimeter is working correctly.
Power-on Inspection
Before connecting the instrument to a power source, please select the AC
voltage selector on the rear panel of your multimeter according to the power
supply. Then connect the power line to the socket on the rear panel of the
multimeter.
Note: To avoid electric shock, make sure that the instrument is correctly
grounded to the earth before connecting AC power.
The boot screen will appear after pressing the power-on button. To restore the
instrument configuration to factory default settings:
Press [Shift] > [Utility] > Store/Recall >Set To Defaults
Default Setup
After setting to defaults, the multimeter should be set to DC voltage
measurements. Other default settings are shown in the following table.

SDM3045X Service Manual 7
Default settings
Menu or System
Option
Default setting
DCV
Range
Auto
Speed
Slow
Filter
Off
Rel
Off
Acquire
Trg Src
Auto
Delay
Auto
Samples/Trigger
1
VMC Out
Pos
Math
Statistics
Hide
Limits
Off
dB/dBm
Off
Ref Value
Off
Display
Display
Number
Hold
Probe Hold
Off
Self Test
The SDM3045X provides self-test functions, including Key Test, LCD Test,
Beeper Test and Chip Test.
Operating Steps:
1. Press [Shift] > [Utility] > Test /Admin > Board Test
2. To test the keys:
Select Key to enter the key test interface. The on-screen lathy rectangle
shapes represent the keys on the front panel. Test all keys and knobs and
you should also verify that all the backlit buttons illuminate correctly.
3. To test the LCD screen:
Select LCD to enter the screen test interface, the screen shows the
message:” Press ‘Change’to change Press ‘Done’to exit“. Press Change
to start the test and observe if the screen has any defects (missing pixels,
for example).
4. To test the beeper:
Press Beeper to test the beeper. Under regular circumstances, pressing
Beeper once and the instrument will beep once.
5. Test the chips:
Press Chip > Start to start chip test. Determine whether the chip test
passes according to the interface message.

Performance Verification
Use the performance verification tests in this section to verify the
measurement performance of the instrument using the instrument’s
specifications listed in the product data sheet.
Performance verification tests are recommended as an acceptance test when
you first receive the instrument or after performing calibration. If the instrument
fails performance verification, calibration adjustment or repair is required.
Performance verification test items
⚫Zero Offset Verification
⚫DC Voltage and DC Current Gain Verification
⚫Frequency Accuracy Verification
⚫AC Voltage and AC Current Verification High Current Verification
⚫Capacitance Verification
Recommended Test Equipment
The recommended test equipment for the performance verification and
calibration is listed below. If the exact instrument is not available, substitute
calibration standards of equivalent accuracy.
Application
Recommended Equipment
Zero Offset Verification
Keysight 34172B
DC Voltage and DC Current Gain
Verification
Fluke 5522A
Frequency Accuracy Verification
Siglent SDG2000X Series Function/Arbitrary
Waveform Generator
AC Voltage and AC Current
Verification
Fluke 5522A
Capacitance Verification
Fluke 5522A
Performance verification step
1. Connect the calibrator to the input terminals correctly.
2. Configure each function and range in the order shown in the table
corresponding to the DMM model number. Provide the input shown in the
table.
3. Make a measurement and return the result. Compare measurement results
to the test limits shown in the table. (Be certain to allow for appropriate

SDM3045X Service Manual 9
source settling time.)
Test Considerations
⚫Ensure that the test ambient temperature is stable and between 18°C and
28°C. Ideally the calibration should be performed at 23°C±2°C.
⚫Ensure ambient relative humidity is less than 80%.
⚫Allow a 30 minute warm–up period with a copper short connected.
⚫Ensure the measuring rate is set to “slow”for DCV, ACV, DCI, ACI and
2-Wire/ 4-Wire Resistance measurements.
Zero Offset Verification
Input
Function
Range
Error from Nominal
(1 year)
Open
DC Current
600 μA
±0.03 μA
6 mA
±0.3 μA
60 mA
±3 μA
600 mA
±60 μA
6 A
±500 μA
10 A
±4 mA
Short
DC Volts
600 mV
±60 μV
6 V
±600 μV
60 V
±6 mV
600 V
±60 mV
1000 V
±600 mV
Short
4-wire Ohms
600 Ω
±60 mΩ
6 kΩ
±600 mΩ
60 kΩ
±6 Ω
600 kΩ
±60 Ω
6 MΩ
±300 Ω
60 MΩ
±3 kΩ
100 MΩ
±30 kΩ

DC Voltage and DC Current Gain Verification
Input
Error from Nominal
(1 years)
Voltage
Function
Range
-600 mV
DC Volts
600 mV
±180 μV
600 mV
-6 V
6 V
±1.8 mV
6 V
10 V
60 V
±8 mV
-60 V
±18 mV
60 V
-600 V
600 V
±180 mV
600 V
-500 V
1000 V
±700 mV
1000 V
±800 mV
Input
Error from Nominal
(1 years)
Current
Function
Range
600 μA
DC Current
600 μA
±0.33 μA
6 mA
6 mA
±3.3 μA
60 mA
60 mA
±33 μA
600 mA
600 mA
±780 μA
6 A
6 A
±12.5 mA
60 A
60 A
±29 mA
Input
Error from Nominal
(1 years)
Resistance
Function
Range
600 Ω
4-wire Ohms
600 Ω
±540 mΩ
6 kΩ
6 kΩ
±3 Ω
60 kΩ
60 kΩ
±30 Ω
600 kΩ
600 kΩ
±540 Ω
6 MΩ
6 MΩ
±7.3 kΩ
60 MΩ
60 MΩ
±513 kΩ
100 MΩ
2-wire Ohms
100 MΩ
±1.78 MΩ

SDM3045X Service Manual 11
Frequency Accuracy Verification
Input
Error from Nominal
(1 years)
Vrms
Frequency
Range
60 mV
500 kHz
200 mV
±50 Hz
0.3 V
20 Hz
2 V
±0.2 Hz
AC Voltage and AC Current Verification
Input
Error from Nominal
(1 years)
Vrms
Frequency
Range
600 mV
1 kHz
600 mV
±2 mV
50 kHz
±12.4 mV
100 kHz
±18.1 mV
6 V
1 kHz
6 V
±50 mV
50 kHz
±124 mV
100 kHz
±184 mV
0.6 V
1 kHz
60 V
±84.8 mV
6 V
1 kHz
±128 mV
60 V
45 Hz
±1.22 V
20 kHz
±500 mV
50 kHz
±1.24 V
100 kHz
±1.84 V
600 V
1 kHz
600 V
±5 V
50 kHz
±12.4 V
100 kHz
±18.4 V
750 V
1 kHz
750 V
±6.2 V
250 V
50 kHz
±5.4 V
75 V
100 kHz
±3.4 V

Input
Error from Nominal
(1 years)
Irms
Frequency
Range
20mA
1 kHz
20 mA
±0.12 mA
10 kHz
±0.54mA
2mA
1 kHz
200 mA
±0.41 mA
200mA
1 kHz
±1.2 mA
10 kHz
±5.4 mA
20mA
1 kHz
2 A
±6.1 mA
2A
1 kHz
±14 mA
10 kHz
±54 mA
200mA
1 kHz
10 A
±26 mA
10A
1 kHz
±65 mA
10 kHz
±270 mA
Capacitance Verification
Input
Error from Nominal
(1 year)
Capacitance
Range
2 nF
2 nF
±0.07 nF
20 nF
20 nF
±0.3 nF
200 nF
200 nF
±2.9 nF
2 μF
2 μF
±30 nF
20 μF
20 μF
±300 nF
200 μF
200 μF
±2.9 μF
10000 μF
10000 μF
±250 μF

SDM3045X Service Manual 13
Assembly Procedures
This chapter describes how to remove the major modules from the SDM3045X.
To install the removed modules or replace new modules, please follow
corresponding operating steps in reverse order.
Security Consideration
Only qualified personnel should perform the disassembly procedures.
Whenever possible, disconnect the power before removing or replacing.
Otherwise, personal injuries or damages to the components may occur.
Avoid Electric Shock Hazardous voltages exist on the LCD module and
power supply module. To avoid electrical shock, disconnect the power cord
from the multimeter and then wait at least three minutes for the capacitors in
the multimeter to discharge before beginning the disassembly.
Preventing ESD Almost all electrical components can be damaged by
electrostatic discharge (ESD) during handling. Component damages can occur
at electrostatic discharge voltages as low as 50 volts. The following guidelines
will help preventing ESD damage when servicing the instrument or any
electronic device.
◆Disassemble instruments only in a static-free work area.
◆Use a conductive work area to reduce static charges.
◆Use a conductive wrist strap to reduce static charge accumulation.
◆Minimize handling.
◆Keep replacement parts in original static-free packaging.
◆Remove all plastic, foam, vinyl, paper and other static-generating materials
from the immediate work area.
◆Use only anti-static solder suckers.
Required Tools
Use these tools to remove or replace the modules in the multimeter:
⚫T10 hexagon screwdriver
⚫2# Phillips screwdriver
⚫Needle-nose pliers

Disassembly Procedures
1. Turn off the power and remove all measurement leads and other cables,
including the power cord, from the instrument before continuing.
2. Rotate the handle to the upright position and remove it by pulling outward
where it attaches to the case.
3. Unscrew the four captive screws in the rear bezel and remove the foot pads
as indicated by the arrow shown below