What are the common methods for circuit board maintenance？

We all know that control systems are very expensive. It is precisely for this reason that when they malfunction, most of us choose to repair them to solve the problem. This is also determined for controlling costs and striving for the maximum economic benefits. We won't have to replace the new board unless the following several situations occur. The service life of the circuit board has expired. The damage to the circuit board has reached a point where it cannot be repaired. The circuit board has been repaired many times and there have been continuous problems. Circuit board repair can still help friends solve urgent problems in most cases. Here I'd like to share some maintenance tips with you all for your reference.

Circuit board composition

The circuit board is mainly composed of solder pads, vias, mounting holes, wires, components, connectors, fillers, electrical boundaries, etc. The main functions of each component are as follows:

Pad: A metal hole used for soldering the pins of components.

Vias: There are metal vias and non-metal vias, among which metal vias are used to connect the pins of components between different layers.

Mounting hole: Used for fixing the circuit board.

Wire: An electrical network copper film used to connect the pins of components.

Connector: A component used for connecting circuit boards.

Filling: Copper plating for ground wire networks can effectively reduce impedance.

Electrical boundary: It is used to determine the size of the circuit board, and all components on the circuit board must not exceed this boundary.

Circuit board maintenance skills

1.Observation Method for circuit board maintenance

This method is quite intuitive. By carefully inspecting it, we can clearly see the traces of burning. When this problem occurs, when we carry out maintenance and inspection, we should pay attention to the patterns to ensure that no more serious damage occurs when the power is on. When we use this method, we need to pay attention to the following several issues:

The first step is to determine whether the circuit board is damaged by human factors through observation. Mainly observe the following aspects to determine.

① Whether the corners of the board are deformed; Whether the chip is deformed and whether other components are deformed.

② Are there any signs of prying on the chip socket?

③ Check if the circuit board chips are inserted properly. This can cause damage when powered on, so be cautious.

④ Are the corresponding short-circuit terminals on the circuit board inserted incorrectly or in reverse?

The second step is to carefully observe the components related to this circuit board. Every capacitor, resistor, etc. should be examined to see if there is any blackening. Since resistance cannot be observed, it can only be measured with instruments. The relevant faulty parts should be replaced in time.

The third step is to observe the integrated circuits on the circuit board, such as the CPU, AD and other related chips. If any bulging, burning or other related conditions are observed, they should be modified in time.

2. Static measurement method for circuit board maintenance

In circuit board maintenance, the observation method often makes it difficult to detect some problems, unless there is a very obvious burnout or deformation. However, most problems still require measurement with a voltmeter to reach a conclusion. The circuit board components and related parts should be inspected one by one.

The maintenance steps should be carried out in accordance with the following process, and the main practical tool is a multimeter.

The first step: Conduct a short circuit detection between the power supply and the ground to identify the cause.

Step 2: Check if the diode is functioning properly.

Step 3: Check if there is a short circuit or even an open circuit in the capacitor.

Step 4: Check the indicators of the integrated circuits related to the circuit board and related components such as resistors.

3. Online measurement method for circuit board maintenance

The online measurement method is frequently used by manufacturers. It is very necessary to specially build a universal debugging and maintenance platform for the convenience of maintenance. When conducting measurements with this method, it is necessary to pay attention to following the steps below.

The first step is to power on the circuit board and check if there is any overheating of the components. If so, replace the relevant components after inspection.

Step 2: Inspect the gate circuits corresponding to the circuit board, observe whether there are any issues with the logic, and determine the quality of the chip.

Step 3: Test whether the output of the crystal oscillator in the digital circuit is normal