What are the advantages and applications of flexible microcircuits?
FPC Reinforcement Types
Criteria for Classification of electronic Component Classes
Four softwares suitable for beginners to draw PCB circuit boards
What information is needed for SMT processing?
What are the advantages of small and medium batch SMT processing?
PCB related knowledge- The purpose of each layer of the PCB
How to do heat resistance testing for PCB board
Detailed explanation of rigid-flex board and IC carrier board
PCBA prototype procedure
Defects which can be detected by the SPI
What are the spacing requirements for designing PCB circuit boards?
What are the classification and advantages of PCB metal substrates?
Difference between the processing technology of 1Layer AL PCB and 2Layer AL PCB
Introduction of FPC Cable and its usage
advantages of Shenzhen SMT assembly factory
inspection items before PCB ordering
usages of ceramic substrates
main applications of PCB boards
Cost-effective PCB product services
How to check short circuit of a circuit board during manual soldering
Identify the polarity of electronic components during PCBA processing
Means Which Can Prevent Component Shifting in SMT Processing
Skills of PCB prototype manual soldering
Reasons for the shift of Components in the SMT Process
Seven Types of PCB Probes
What Should Be Paid Attention to in Layout of High-frequency PCB
Precautions for PCB CCL Selection
Advantages of LED Plant growth light
Advantages of using LED grow lights to grow industrial hemp
Detailed explanation of PCB manufacturing process and precautions
Detailed explanation of PCB manufacturing process and precautions
How to draw multilayer PCB on Altium Designer
Three basic elements of interference and how to suppression them.
Decrease interference between digital circuit and analog circuit
SMT Component Placement Process Of Parts : Manual Placement
SMT factory incoming PCB material inspection
Basic concepts commonly used in PCB design
Ideas and principles of High speed PCB layout
Component layout rules and safety distance considerations
SMT assembly process quality specification
5 points in PCB layout
Professional interpretation of SMT
Advantages and disadvantages of different PCB surface treatment
Special process in PCB prototype
Why the via hole become open after component assembly
Keep the cost of the PCB as low as possible
what are the causes of PCB board heating radiation problem
Pad size and via diameter dimensions consideration in PCB prototyping
How to Judge the Acceptance of PCB Quality
Which Color Circuit Board Sells the Most Expensive
Method to Solve the Noise Interference of Power Supply on High-frequency PCB Board
Disassembly Skills of Chip Components on PCB
What Factors Should Be Considered in the Selection of High-frequency PCB CCL
How to Place Special Components during PCB Layout
What Are the Functions of Capacitors in Circuits?
Testing Techniques for Common Electronics Components
What to do if There is a Short Circuit on the PCB
Desoldering Principles and knowhow during PCBA Processing
Black Oxidation of the Inner Layer of the Multilayer PCB
How to Ensure the High-performance Design of PCB
What Is the Printing Process of SMT Solder Paste?
PCB without fiducial mark, Is There Any Way to do SMT for It
What Are the Benefits of Reserving Break-up Tab for PCB Production
How Does SMT Affect PCB Production Time and Speed It Up
Classification of PCBs from three aspects
Common Problems and Solutions for Dry Film pasting during PCB Manufacturing process
Several Elements to Inspect after PCB Design
What is a halogen-free circuit board?
What Do Capacitive Coupling and Decoupling Mean?
What Are the Differences Between PCB Paste Mask and Solder Mask?
How PCBA Is Packaged and Shipped
How long can PCBA finished products be stored?
What Are the Differences and Relations Between PCB, PCBA, and SMT?
PCB Baking Specifications
PCB "Solder Mask Tenting" and "Solder Mask Opening"
Five reasons for PCB deformation and six solutions
Importance of first article inspection of PCBA board
Temperature zone standard for SMT reflow soldering
Small and medium volume PCB manufacturers in China
The main reason for PCBA cleaning
For power filter, the more capacitors, the better?
What does PCBA programming mean?
Content of PCB incoming testing
What conditions must be met for PCB circuit board soldering?
What is Blind via and Buried via
PCBA Manufacturers Temperature and Humidity Sensitive Components Management

Testing Techniques for Common Electronics Components

The core of electronic equipment is the circuit board, and the circuit board is composed of a large number of various types of electronic components. If the equipment malfunctions or short-circuits, most of it is caused by the failure or damage of the electronic components. Today China PCBA manufacturer will bring you some correct component inspection techniques.

1. Measure the polarity of each pin of the rectifier bridge

The multimeter is set to R×1k stall, the black test probe is connected to any pin of the rectifier bridge, and the red test probe is used to test the remaining three pins successively. If the reading is infinite, the black test probe is connected to the output positive pole of the bridge stack; if the reading is 4~10kΩ, the pin connected to the black test probe is the output negative pole of the bridge stack, and the remaining two pins are the AC input pin of the rectifier bridge.

2. Judge the quality of the crystal oscillator
First use a multimeter (R×10k stall) to measure the resistance value at both ends of the crystal oscillator. If the resistance value is infinite, it means that the crystal oscillator has no short-circuit or electric leakage; then insert the test pencil into the mains socket and pinch any pin of the crystal oscillator with your fingers, touch the other pin to the metal part on the top of the test pencil. If the neon bulb of the test pencil turns red, it means that the crystal oscillator is good; if the neon bulb doesn’t turn bright, it means that the crystal oscillator is damaged.

3. Unidirectional thyristor inspection

The R×1k or R×100 stall of a multimeter can be used to measure the forward and reverse resistance between any two poles. If the resistance of a pair of poles is found to have a low resistance value (100Ω~lkΩ), then the black test probe is connected to the control electrode, the red test probe is connected to the cathode, and the other is the anode. The thyristor has 3 PN junctions, and we can judge its quality by measuring the forward and reverse resistance of the PN junction. When measuring the resistance between the control electrode (G) and the cathode (C), if the forward and reverse resistances are both being zero or infinite, it indicates that the control electrode is short-circuited or break-circuited. When measuring the resistance between the control electrode (G) and the anode (A), both the positive and reverse resistance readings should be large; when measuring the resistance between the anode (A) and the cathode (C), both the positive and the reverse resistance should be large.

4. Polarity recognition of bidirectional thyristor

The bidirectional thyristor has a main electrode 1, a main electrode 2 and a control electrode. If the resistance between the two main electrodes is measured with a multimeter R×1k stall, the reading should be approximately infinite, and the positive and negative resistance readings between the control electrode and any main electrode are only tens of ohms. According to this characteristic, we can easily identify the control electrode of the bidirectional thyristor by measuring the resistance between the electrodes. When the black test probe is connected to the main electrode 1 and the red test probe is connected to the control electrode, the measured forward resistance is always smaller than the reverse resistance. Therefore, we can easily identify the main electrode 1 and the main electrode 2 by measuring the resistance.

5. Check the quality of the light-emitting digitron
Firstly, set the multimeter to R×10k or R×100k stall, and then connect the red test probe to the "ground" leading-out terminal of the digitron (take the common cathode digital tube as an example), and the black test probe will connect to the other leading-out terminals of the digitron in turn. The seven segments should be illuminated separately, otherwise the digital tube is damaged.