Ordinary electronic products have been used for a long time, and the circuit board will be covered with dust. More dust or high air humidity will cause corrosion and short circuit to the circuit board, and damage parts and circuit boards. Therefore, when there is more dust on the circuit board, it is necessary to clean it. Precision circuit boards such as system board video cards, sound cards, and network cards are cleaned before leaving the factory. The main purpose is to remove harmful substances such as soldering flux and hand sweat (although all operators on the consumer line wear gloves) that are attached to the circuit board during the consumption process. For circuit board manufacturers, they use special cleaning fluid (commonly known as cleaning water) to wash the board. For ordinary users, due to limited conditions, it is impossible to operate like the circuit board manufacturer, but only need to be careful and careful when operating; Cleaning circuit boards is not a difficult and terrible thing.

1. Preparation before cleaning Before cleaning, all connectors on the circuit board, including jumper plug, card board, battery and IC, must be carefully pulled out one by one. Potentiometers, transformers and solenoid coils (inductive coils) must also be removed from the circuit board, [Note: Non electronic professionals should not stop this operation. If they do not have electronic expertise, they can easily damage parts and circuit boards during disassembly. Fortunately, there are basically no such components on computer related circuit boards.] Therefore, once water enters into such components, it is very difficult for water droplets in their gaps or between wire turns to be blown out by compressed air and moisture to be dried. It is necessary to make records one by one during disassembly, To ensure that no error will occur during recovery after cleaning. At the same time, check whether the electrolytic capacitor on the circuit board has liquid leakage or bulge on the top. If yes, remove it and make a record so as to replace it with new products of equivalent value after the liquidation of the circuit board. For the circuit board of computer power supply, check whether there are cracks or loose solders between the pad and component pins of its printed circuit, especially the high-power components. If cracks or loose solders are found, repair them immediately. If one is found, repair one, otherwise it is easy to miss.

2. Cleaning

⑴. Before cleaning, use a clean soft paint brush (one inch wide brush is better) and compressed air with a pressure of about 0.1Mpa [1kg/cm2] to remove the dust on the circuit board.

⑵. Special cleaning liquid (commonly known as board washing water) can be used for cleaning circuit boards, and this liquid can be bought at special stores. If there is no board washing water, you can do as follows: (Usually we don't need to use board washing water) Use tap water to wash the board first, pay attention to the water flow to be soft, not too strong, and use a soft brush to carefully brush the board while flushing, both sides of the circuit board are like this.

⑶. Then use a soft brush dipped in neutral soap to carefully and quietly clean each center of the circuit board, especially the jumper plug, the inside and bottom of the slot (CPU slot, AGP slot, PCI slot, memory slot), the bottom of the IC socket, the bottom of the North South Bridge chip, BIOS chip and each other IC chip, and the bottom of the large capacitor. During operation, be careful not to touch the small capacitors and other components that are installed vertically; If it is found that the soap foam washed is very dirty, it must be washed with clean water and then brushed again with soap until the soap foam washed is white.