How to detect whether each crystal oscillator on the motherboard is vibrating

Methods and skills for detecting the quality of crystal oscillator:

1.Use a multimeter (R 10K gear) to measure the resistance value of both ends of the crystal oscillator, if it is infinite, it means that the crystal oscillator has no short circuit or leakage; Then insert the tester into the mains jack, pinch any pin of the crystal oscillator with your fingers, and touch the other pin to the metal part of the top of the tester. If the neon bubble does not shine, it means that the crystal oscillator is damaged.

2.Measuring the capacitance with a digital capacitance meter (or the capacitance file of a digital multimeter) shows that the capacitance of the damaged crystal oscillator is significantly reduced (the normal capacitance of different crystal oscillators has a certain range).

3.Shake it close to your ear, and if there is a sound, it must be bad (the crystal inside has been broken, and the frequency has changed if you can still use it).

4.Test the output pin voltage. Under normal circumstances, it is about half of the power supply voltage.

Because the output is a sine wave (the peak-to-peak is close to the source voltage), when tested with a multimeter, it is almost half. 5.Measured with substitution or oscilloscope.

So how to use a multimeter to measure whether the crystal oscillator is vibrating?

You can use a multimeter to measure whether the voltage of the two pins of the crystal oscillator is half of the working voltage of the chip, for example, if the working voltage is 5V, whether the measured voltage is about or so. Another example is:

If you touch the other foot of the crystal with tweezers, the voltage changes significantly, which proves that it is vibrating.

Tips: is to get a battery connected to both ends of the crystal oscillator and put the crystal oscillator to the ear to listen carefully, when you hear the sound of da-da, it means that it vibrates, it is good!

Use the voltage level to measure the crystal oscillator on both pins, which means that the motherboard has vibrate. This can only be approximate. The waveform can be seen with an oscilloscope. I haven't used anything like a frequency meter either.

There are four main types of crystal oscillators on computer motherboards:

1. Clock crystal oscillator: The clock crystal oscillator and the clock are connected to the circuit, and the frequency is that after the crystal oscillator is damaged, it will cause the fault that the motherboard cannot be started. When working normally, the voltage between the two pins is 1.

2. Real-time crystal oscillator: The real-time crystal oscillator is connected to the Nanqiao chip, and the frequency is that after the crystal oscillator is damaged, it will cause the fault that the time part is accurate or cannot be started. In normal operation, the voltage between the two pins is left and right.

3. Sound card crystal oscillator: The sound card crystal oscillator is connected to the sound card chip, and the frequency is MHz, after the crystal oscillator is damaged, it will cause sound deterioration or silent failure. In normal operation, the voltage of the two pins is 1.

4. Network card crystal oscillator: The network card crystal oscillator is connected to the network card chip, and the frequency is 25000 MHz, after the crystal oscillator is damaged, it will cause the function of the network card to fail. When working normally, the voltage between the two pins is.

The computer motherboard generally has two crystals, one is responsible for the clock circuit, and a coin cell battery is responsible for power supply, so that your computer time can keep moving, even if it is turned off, the frequency of this crystal is, and the red circle in the figure below is. This crystal is used in many clock circuits, such as alarm clocks and wall clocks at home.

There is also a crystal that provides a clock for the CPU, and the frequency is:

This kind of crystal electronics market is available, very cheap, a few cents to 1 3 yuan.

The frequency generator must be on the motherboard manual.

Upstairs is teasing, and the identification is complete.

The easiest way is to buy a multimeter that can measure crystal oscillators. If you want to measure the accuracy of the parameters, you can use the CZ-8C impedance meter to measure, but it is more expensive.

The crystal oscillator is the clock frequency reference, and if it breaks, the computer will not boot.

Once you are in the BIOS settings, press F10 to save it.

In addition, look at the jumper of the COMS motherboard, whether it is in the clear COMS state.

If there is still a problem, it is that the hardware is a little conflicting, such as interrupting the allocation of fights. Remove some of the cost-based hardware and boot it up. There is also a hidden defect in the memory, which will also cause the boot state to need to be reset.

If the hardware connection is normal, set up the BIOS, if it still doesn't work, upgrade the BIOS, it should solve the problem.

Do you understand weak electricity.

Or will you use a multimeter?

You can use a multimeter to judge the quality of the crystal oscillator.

A clock is to be crystalline.

In fact, the most important thing is to provide working frequency for each chip, and each chip needs frequency to work, but the chip itself cannot produce frequency, so let the crystal oscillator cooperate with the ** module in the clock chip to generate a certain frequency.

Typically, there are three on the motherboard, one on the side of the clock chip or the southbridge chip (which provides the different frequencies required by each chip). One is on the edge of the south bridge (required for the clock), and the other is 25MHz on the edge of the network card chip (specifically for the network card).

1. In fact, crystal oscillators are all active, that is, crystal resonators + oscillation circuits. The most commonly used resonator is a thin sheet of ground quartz.

2. The so-called passive crystal oscillator usually refers to the crystal resonator; Because there is no oscillation circuit part, it is not really an oscillator.

3. EPM7128S has two globals

clock(gclk1 and gclk2). The active crystal oscillator can be connected directly, which one do you want to connect?

The source crystal oscillator is what we call a crystal resonator, which cannot be used alone, and requires an external circuit to play a leading role.

Active crystal oscillator is to make the passive crystal oscillator and the first circuit together, and it can be used when it is energized.