How to check the PCB board short circuit?
Second, if it is artificial welding, it is necessary to develop good habits:
1. Visually inspect the PCB board before soldering, and use a multimeter to check whether the critical circuit (especially the power supply and ground) is short-circuited;
2. Use a multimeter to measure whether the power supply and ground are short-circuited after each chip is soldered.
3, do not smash the soldering iron when soldering, if the solder is rubbed onto the soldering feet of the chip (especially surface mount components), it is not easy to find.
Third, it was found that there was a short circuit. Take a board to cut the line (especially suitable for single/double board), after each secant, each part of the function block is energized separately and gradually eliminated.
Fifth， If there is a BGA chip, since all the solder joints are invisible by the chip cover, and it is a multi-layer board (more than 4 layers), it is better to separate the power of each chip at the time of design, using magnetic beads or 0 ohms. The resistor is connected so that when the power supply is shorted to the ground, the magnetic bead is detected and it is easy to locate a certain chip. Due to the difficulty in soldering the BGA, if it is not the machine's automatic soldering, the adjacent power supply and ground solder balls will be short-circuited with a little care.(china pcb manufacturer)
Sixth, small size surface mount capacitors must be careful when soldering, especially the power supply filter capacitor (103 or 104), the number is large, it is easy to cause the power supply and ground short circuit. Of course, sometimes the luck is not good, the capacitor itself is short-circuited, so the best way is to check the capacitance before soldering.