In fact, there are many ways to measure differential crystal oscillators. It mainly depends on what method you choose, because the steps and operation methods of different measurement methods are different.

Differential crystal oscillator measurement skills
Skill 1: Traditional measurement method
The traditional measurement method is to use substitution method or oscilloscope measurement. How to use a multimeter to measure whether the crystal oscillator starts to vibrate? You can use a multimeter to measure whether the voltage of the two pins of the crystal oscillator is half of the chip working voltage. For example, if the working voltage is 5V, it is about 2.5V. In addition, if you touch the other leg of the crystal with tweezers, the voltage will change significantly, proving that it has started to vibrate, indicating that it is a good differential crystal oscillator.

Skill 2: Technical measurement method
Generally, technicians in enterprises will use an R10k multimeter to measure the resistance value at both ends of the crystal oscillator when measuring and checking the powder crystal oscillator. This method is a technical measurement method, which many technicians like, mainly because the test method is relatively simple.
If it is infinite, it means that the crystal oscillator has no short circuit and leakage. Then insert the electric probe into the power socket, pinch any pin of the crystal oscillator with your fingers, and touch the other pin to the metal part on the top of the electric probe. If the neon bulb in the electroprobe is red, it means that the crystal oscillator is good; if the neon bulb is not on, it means that the crystal oscillator is damaged.

Tip 3: Multimeter test
Use the multimeter R10k block to measure the resistance value at both ends of the crystal oscillator. If it is infinite, it means that the crystal oscillator is not short-circuited and leaking. Use a digital capacitance meter (or the capacitance of a digital multimeter) to measure its capacitance. Generally, the capacity of a damaged crystal oscillator is significantly reduced. The normal capacity of different crystal oscillators has a certain range.

Tip 4: Test by listening to the sound
Shake it close to your ear, and it must be broken if there is a sound. The internal crystal has been broken, and if it can still be used, the frequency has changed. This is a relatively simple test method. You can also directly use the test output pin voltage. Under normal circumstances, it is about half of the power supply voltage. Because the output is a sine wave (the peak value is close to the source voltage), when tested with a multimeter, it is almost half.

Tip 5: Use substitution method or oscilloscope to measure
Use a multimeter to measure whether the voltage of the two pins of the crystal oscillator is half of the chip's operating voltage. For example, if the operating voltage is 5V, the measured voltage is about 2.5V. In addition, if you touch the other pin of the crystal with tweezers, the voltage changes significantly, proving that it is vibrating. These techniques are similar to the first method, and you can use some substitute products for testing.