The crystal oscillator structure and design are more complex
This, in addition, is a very fragile component
When it doesn't work properly, it affects the entire circuit
It is especially important to learn how to test crystal oscillators
Next, let's take a look at it together
Three simple ways to test crystal oscillations
#01
Oscilloscope detection method
The crystal oscillator produces a sine wave when excited, and it is appropriate to look at the waveform representing the sine wave on the clock pin. If the clock is not working properly, replace the crystal.
When the display comes in without high voltage symptoms, check the crystal with an oscilloscope to find that the waveform is very unstable, replace the microprocessor to solve the problem of no high voltage, and the crystal oscillator waveform shows a perfect sine wave.
#02
Frequency counter detection method
Measurements must be taken when the device is "on". Place the probe of the meter or frequency counter on the crystal pin and read the measured value. Make sure that you are using a frequency counter table that is in a higher range than the crystal frequency being checked.
If the crystal is 8 mhz, then the instrument used should have a range capable of checking that frequency. Assuming that the crystal oscillator reads 2.5 mhz, it can be known that the crystal is not working properly and needs to be replaced. Ordinary digital multimeters usually have a small range of inspection frequencies.
#03
Test circuit detection method
Display devices are capable of displaying characters and symbols, and are increasingly used in electronic devices. LED (light-emitting diode) digital tubes and liquid crystal displays are the most commonly used display devices.
Typically, the crystal oscillator is placed in the feedback network of the transistor. If it oscillates and the LED is lit, it means that the crystal oscillator is running. If the crystal oscillator does not work, the LED will go out. Other expensive crystal detectors do not use LEDs as indicators, but instead use panel meters to indicate whether the crystals are working properly.
| summary
From this article, we can understand that testing the crystal oscillator is not an easy task. There are many ways to check, only choose a practical and effective method to achieve the effect of doubling the results with half the effort, like this article of you, please collect it for later!