For electronic engineers, the manufacture of [the circuit board](jlcpcb.com/m) is a necessary step, but the # shortcut of the circuit board # is a much common problem during the manufacture of the circuit board. A shortcut for the [Printed Circuit board](jlcpcb.com/m) may cause components to burn out and the system to fail, so we must pay attention to it. Today we would like to analyze the main reasons which cause the shortcut and how we can detect circuit board shortcuts. 1. There are two kinds of short cuts, one is that the[PCB](jlcpcb.com/m) itself has reached a certain service life period. 2. The second case is the inspection job did not do very well during the manufacturing period. However, these small mistakes in production will do great harm to the whole PCB circuit board, which is likely to lead to scrap. So **how do we check and prevent[ Printed circuit board shortcut](jlcpcb.com/m)?** 1 if it is manual welding, we have to develop good habits, First, before welding, visually check the PCB board, and use a multimeter to check whether the key circuit (especially the power supply and ground) is short or not; Secondly, every time a chip is welded, a multimeter should be short used to measure whether the power supply and ground are shortcuts. In addition, do not randomly shake the iron when welding, if the solder to the chip on the pad (especially the table sticker components), it is not easy to check. 2. Open the PCB diagram on the computer and light up the short-circuited network to see which place is nearest and most easily connected to a piece. Pay special attention to the IC internal short circuit. 3. Shortcuts come up. Take a board to cut the line (especially suitable for single/double deck), after cutting the line, electrify each part of the functional block, and exclude one part. 4. Use short circuit location analyzer, such as Singapore PROTECH CB2000 short circuit tracker, Hong Kong Linzhi TECHNOLOGY QT50 short circuit tracker, British POLAR ToneOhm950 multilayer board short circuit detector, etc. 5. If there is A BGA chip, because all solder joints are covered by the chip and cannot be seen, and it is a multi-layer board (more than 4 layers), it is better to separate the power supply of each chip in the design and connect it with magnetic beads or 0-ohm resistance. In this way, when the power supply is a shortcut to the ground, disconnect the magnetic bead detection and it is easy to locate a certain chip. Due to the difficulty of BGA welding, if the machine is not automatic welding, a little attention will short-circuit the adjacent power supply and the ground two welding balls. 6. the small size of the table paste capacitor welding must be careful, especially the power filter capacitor (103 or 104), the number is large, it is easy to cause the power supply and ground short circuit. Of course, sometimes, unfortunately, the capacitor itself is short-circuited, so the best way is to check the capacitor before welding.