The biggest problem encountered in the maintenance of electronic products is the short circuit. The short circuit on the PCB is quite harmful, ranging from burned components to large PCB scraps. Therefore, in PCB proofing, we must master every production detail and try to Prevent Short Circuit.
1. If it is manual soldering, visually inspect the PCB board before soldering, and use a multimeter to check the key circuits (especially power and ground) to see if there is a short circuit; each time a chip is soldered, use a multimeter to measure the power and ground to see if it is Short circuit.
2. Open the PCB diagram on the computer, light up the short circuit of the network, and see which is the closest and easiest to connect to. Special attention should be paid to short circuits inside the IC.
3. Found the short circuit phenomenon of the PCB circuit board, take a board cutting line (especially suitable for single-sided PCB/double-sided PCB board), power on each part of the functional block after cutting the line, and partly exclude it.
4. Use a short-circuit locating analyzer to detect short-circuit problems in multi-layer circuit boards.
5. Care must be taken when welding capacitors for small-size tables, especially the power filter capacitors (103 or 104), which are large in number, and can easily cause a short circuit between the power supply and the ground of the circuit board.
6. If there is a BGA chip, it is best to design the power supply of each chip, with magnetic beads or 0 European resistance connection, when the power supply and the ground are short-circuited, disconnect the magnetic bead detection, so that it is easier to find the chip.