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How should hardware testing be done?

  • Author:Mio
  • Source:www.ic-stocks.com
  • Release on:2019-10-12
When a board is soldered, when it is checked whether the board can work normally, it is usually not directly supplied to the board. Instead, follow the steps below to ensure that there is no problem after each step and then power on.


1. Is the connection correct? Checking the schematic is critical. The first check focuses on whether the power and network nodes of the chip are labeled correctly, and also pay attention to whether the network nodes overlap. Another focus is on the original package, the package type, and the pin order of the package; the package cannot be top view, remember! Especially for non-pinned packages. Check that the connections are correct, including wrong lines, fewer lines, and multiple lines.



There are usually two methods for checking the line: 1) Check the installed circuit according to the circuit diagram, check the installed line one by one according to the circuit connection; 2) According to the actual line, follow the schematic diagram, and check one component for the center. line. Check the wiring of each component pin at a time and check if each location exists on the circuit diagram. In order to prevent errors, the marked lines should usually be marked on the circuit diagram. It is better to use the buzzer of the pointer multimeter ohms to directly measure the component pins, so that the wiring can be found at the same time.

2. Is the power supply shorted? Do not power on before debugging, use a multimeter to measure the input impedance of the power supply, this is a necessary step! If the power supply is short-circuited, it will cause the power supply to burn out or have more serious consequences. When it comes to the power supply part, a 0 ohm resistor can be used as a debugging method. Do not solder the resistor before power-on. Check the voltage of the power supply and then solder the resistor to the PCB to supply power to the rear unit. This will prevent the power-on voltage of the power supply from being abnormal due to abnormal power supply. Add protection circuits to the circuit design, such as using recovery fuses and other components.



3. Installation of components. Mainly to check for polar components, such as light-emitting diodes, electrolytic capacitors, rectifier diodes, etc., and whether the pins of the transistor correspond. For the triode, the order of the different manufacturers of the same function is different. It is best to test it with a multimeter.



Open circuit and short circuit test first to ensure that there will be no short circuit after power-on. If the test points are set well, you can do more with less. The use of a 0 ohm resistor is sometimes also beneficial for high speed circuit testing.