Shenzhen Xingkexun Electronics Co., Ltd. Contact: Mr. Wu Tel: 0755-81486688
Address: Block D, Yiyuanda Scientific Research Park, Shilong Community, Shiyan Street, Baoan District, Shenzhen, Guangdong.
Visual inspection method
You can check and find the fault of smt patch through vision, smell, hearing and touch.
Visually check the wiring, smt patch joints, and components for errors. After confirming that there is no error, install the battery. After powering on the radio, listen for abnormal sounds. If it is hot, see if the electrolytic capacitor has cracks.
Use MF47 type multimeter to check whether the resistance value of the resistor chip components in the circuit is correct, check whether the capacitor is disconnected, breakdown or leakage, and check whether the crystal diode and transistor are normal.
3. SMT chip processing voltage method
Use MF47 type multimeter DC voltage to check the power supply, whether the static working voltage of the transistor is correct. If the cause is not found correctly, the AC voltage value can also be detected.
4. Wave method
Use an oscilloscope to check the circuit waveform. At this time, you need to do it with an external signal input. Use an oscilloscope to check the output waveform of each transistor.
5. Current method
Use the MF47 multimeter DC current scale to detect the static current of the collector of the transistor to see if it meets the standard.
6. Component substitution method
After the above inspections, if a component is suspected to have a problem, the component can be replaced with an intact component of the same specification. If the circuit works normally after the replacement, it means that the original replaced component is damaged. This method should not be used for components with higher cost, because if it is not the component is damaged, unnecessary waste will be caused. For the component with higher cost, the component must be determined to be replaced before it can be replaced.
7. Step by step separation method
The step-by-step inspection separation method can adopt the method of checking from the front to the back, or the method of checking from the back to the front. Set test breakpoints between different levels, so that the detection range can be narrowed during the test, and it can be checked step by step, so it is easier to check the location of the fault point.
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