When encountering things, it is necessary to divide it into two parts, and the crystal oscillator is no exception. The crystal oscillator stop vibration should be analyzed from different angles of internal and external reasons. Below we analyze the crystal oscillator stop vibration based on internal and external factors.
Analysis of the Causes of Crystal Oscillation Stopping

There are many engineers who are encountering the problem that the crystal oscillator is on the circuit board, it starts to vibrate for a while, but does not vibrate for a while, or it can work normally after blowing it with a hair dryer. At this time, I began to doubt whether the crystal oscillator is the problem. In fact, we can't draw too early conclusions. We must grasp the core of the problem before we can make a correct judgment.
Materialist dialectics refers to a philosophical approach to the study of nature, society, history and thinking. In fact, it is to tell us that when we encounter something, we should divide it into two, and the crystal oscillator is no exception. We should analyze the stop of the crystal oscillator from different angles of internal and external reasons. Let's analyze the stop vibration of the crystal oscillator based on internal and external factors:
1. Eliminate the bad external components, because the external components are nothing more than resistors and capacitors, so you can easily identify whether they are defective products.
2. Eliminate the possibility that the crystal oscillator cannot be used as a vibrating product. Here, you will not stop the test after only trying 1~2 crystal oscillators.
3. Eliminate the possibility of circuit errors, so first try to compare with the recommended circuit of the corresponding type of circuit.
4. The capacitance at both ends of the crystal can be changed, and the crystal oscillator can work normally. For the size of the capacitance, please refer to the instruction manual of the crystal oscillator. The matching capacitance is very important.
The crystal oscillator itself is the reason, the chip is broken, the impedance is too large, the frequency is poor, the crystal pulling force is insufficient, and the parasitic reaction is too large. Or on the circuit, the load capacitance or the stray capacitance caused by circuit design or processing has a large dispersion, and the voltage across the crystal is insufficient, which will also cause the crystal oscillator to stop vibrating!
If you encounter such a problem, firstly check whether the frequency parameters of the crystal oscillator and the resistance of the crystal oscillator are within the required range, if so; secondly, check whether the welding temperature of the crystal oscillator will be high, causing the first For secondary damage, the welding temperature is generally required to be around 250 degrees or lower, and the maximum should not exceed 300 degrees. If these are all within the required range, it is necessary to consider whether it is a problem of the entire microcontroller circuit.
Detecting crystal oscillator parameters and adjusting the soldering temperature can be done easily. If the problem of the single-chip microcomputer circuit can be solved by a solution provider, it is also necessary to check whether the crystal oscillator has air leakage. This problem will also occur in the crystal oscillator in humid weather. It is recommended to replace the crystal with better quality.