What are the causes of chassis leakage, and what are the causes of chassis leakage?

The most authoritative: the chassis "leakage" is because of the power supply, a good power supply leakage, and a bad power supply will not leak. **(Jin Hetian, Zhang Yinan)" according to the requirements of the national standard for electromagnetic compatibility (EMC, EMI) and safety.

The main content of EMI design is the design of noise filters. The use of switching power supply filter can effectively suppress the noise in the power grid from entering the equipment (power supply), and can also suppress the noise generated by the equipment (power supply) from polluting the power grid. There are two types of noise, one is common-mode noise and the other is differential-mode noise.

Common mode noise is the current flowing into the ground, and differential mode noise is the current between lines.

In order to suppress these noise pollution, it is necessary to use a filter circuit, and in order to suppress the interference of the common mode, it is necessary to put two capacitors on the input line, L and N, respectively. A big role of the capacitor is to block the straight through cross, (the general noise is a high-frequency signal, which can be approximated to understand the main AC signal). If it is grounded, this part of the interference signal flows into the ground to achieve the effect of filtering.

If it is not grounded, it will flow into the human body if it comes into contact with it. This is what we understand as the phenomenon of leakage. (The voltage of this part is AC, generally up to about 110V).

At the same time, the national standard GB4943 (safety of information technology equipment) stipulates that the relevant electrical appliances (including power supplies) must be grounded. ”

The main reason is that the power supply is not grounded.

100% of the ungrounded chassis has residual power It has nothing to do with the computer hardware and power supply.

Mine is the same, I tested, but nothing exists, I can't figure it out, maybe it's a power supply problem, but this one still has to be done by a professional.

The power plug should be three-way. Because it is necessary to ground the wire.

If it's still a bit, find a conductor like wire and ground the chassis.

That's it.

The single-phase socket should generally be three-phase, the left is the 0 wire, the right is the live wire, and the top is grounded. Use 50 cm steel bars to drive into the ground, and then use a leather wire to connect one end to the back of the chassis, and the first end of the wire is connected to the steel bar, and if it cannot be grounded upstairs, it can be connected to the water pipe.

In addition, if there is a lot of dust in the computer case, it can also cause the case to be electrified.

Try it with a light bulb, if it is lit, it is really grounded, if it is not lit, it is inductive grounding, which is generally caused by the chassis not being grounded.

The power supply leakage is connected to the chassis.

The power supply quality is not up to par or the power supply is connected to the chassis.

How many power cords do you have?

The tripod ground connector of the socket does not fall to the ground.

The address of the power cord does not fall to the ground, or even fake.

The power on the computer's main computer is not off.

Grounded: 100% of the chassis is not grounded, and it has nothing to do with the computer hardware and power supply.

In the power supply circuit, the alternating current is connected to the shell through a small capacitor, and the electrostatic current is very small in the case, and the electricity is not up to people, so don't care. The shell paint is off.

Causes of leakage in the computer case:

1. The air is humid and the electrostatic voltage of the chassis is too high.

If it is a long-term rainy day or the air is relatively humid, it will cause the electrostatic voltage of the computer case to be too high, and the hand will feel numb! If this is the case, then it is recommended to strengthen indoor ventilation, you can put desiccant in the main chassis, and then clean up the dust of the hardware inside the chassis in time, especially the motherboard and power supply.

2. The component pins of some hardware touch the chassis.

Find the hardware that is in contact with the chassis, such as the power supply, which is the most likely to cause the chassis to leak, and the motherboard is not installed properly, and the chassis is deformed, causing the pins on the back of the motherboard to touch the chassis shell, which leads to the chassis vulnerability.

3. The leakage of the main chassis is due to the fact that the power plug does not have a grounding wire.

It is recommended to check this problem first, the vast majority of the main chassis leakage is caused by the power plug without a grounding wire, as long as the chassis is connected through one wire, and then the other end is connected to the bottom or wall.

Computer case leakage solution.

1. Power supply. Remove the power supply from the chassis, disassemble whether the EMI circuit of the power supply is complete, whether the plastic film or mica sheet between the spacer element and the metal shell of the power supply has lost the effect of insulation, and whether the internal capacitance of the power supply has burst pulp, etc., if there is a problem, you can create a high-temperature resistant plastic film to form a shielding barrier between the component and the power supply shell, if it cannot be solved, it is recommended to replace the power supply.

2. Motherboard. When the motherboard leaks, the feeling when you touch it is relatively strong, almost the same as the power leakage, there will be a significant stinging sensation. And the leakage of the computer motherboard will also cause all the components to be electrified, it is best to be able to remove the motherboard from the bare spots, if it is still charged, that is, the internal wiring of the motherboard may be deformed, it is recommended to replace the motherboard.

1.Causes of computer chassis electrification: Computer chassis is electrified, which is a very common phenomenon.

Because the computer power supply of Hewu is a new type of switching power supply, it cancels the traditional transformer step-down, and adjusts the output voltage by changing the on-on and off-time of the switch, which is a new, high-efficiency, low-volume, light-weight power supply. However, since there is no conventional power transformer to separate the mains power from the load, the internal input part of the power supply is "thermoelectric". The output part is isolated by a switching transformer, so it is "cold ground", but because the power supply is in the working state of high voltage, high flat frequency and high power, it will inevitably produce strong static electricity, and the electric tester is used to test the liveness.

However, because the current carried in the chassis is very small, it is generally not dangerous.

2.Solutions for live computer cases: The following are used flexibly.

1. First of all, see whether the three-wire socket and the three-wire plug are connected correctly, and whether the common ground wire, the live wire (i.e. phase wire) of the power supply, and the neutral wire of the electrical return source are correctly connected. (The power supply usually has an imaginary ground terminal, and the voltage at this point is considered to be zero, and most power supplies are negative as the reference ground, so the switch is connected to the positive end of the power supply.)

If the positive terminal of the power supply is set to ground, the switch may be connected to the negative terminal of the power supply. Household electricity 220V AC bar, this is not divided into positive and negative poles, only zero, live wire, generally connected to the live wire. )

2.Open your own case lid. Look at it should be so dirty.

Use a brush (gently sweeping) or a pump (one person to pump, one person to blow) to remove the dust from the computer. (Be careful not to damage the components of the motherboard with too much force) The most important thing is to clear the power box and the vicinity. (You can use a pump and a brush together).

3.If the above method. Still not working, it's a problem with your motherboard and power supply. In your case, it's 220V. It's mostly a problem with your power supply. If you are a DIY expert, you can add a few insulating pads to the motherboard.

It can't be solved anymore. You're going to have to dismantle the power supply. Take the power supply apart and clean it up. It can't be solved anymore. It's going to cost money......Find a new power box and try it.

4. Some users use ordinary lighting electricity at home, only live wire and neutral wire, and no grounding wire, then the three-head socket does not work, it is recommended to use metal wires, the chassis metal outsiders are connected to the earth, some people connect the chassis with water pipes, etc., it is not recommended to use this method, if the power leakage phenomenon really occurs, it is more dangerous.

5. Find a wire, connect one end to your chassis, and the other end to a metal pipe, and bury it in the ground (the safest).

Case leakage refers to the leakage of current in a computer case or its internal parts. Here are some of the reasons that can cause a leak in your case:

1.Power supply question: There is a fault in the power supply itself or the grounding wire of the power supply is in poor contact, resulting in current leakage.

2.Battery problems: If there is an abnormality in the battery, such as a CMOS battery, it may cause current leakage.

3.Aging of components: Prolonged use of internal parts leads to aging and breakage, such as damage to capacitors, which may cause leakage.

4.Incorrect installation: Incorrect installation of the computer's internal parts, such as poor contact of the virtual rock power cord or data cable, may lead to current leakage.

5.Design flaws: Some chassis or components may have design or manufacturing flaws that increase the likelihood of current leakage.

It is important to note that chassis leakage can pose a risk to the user's computer and personal safety. If there is a suspicion that there is a leakage problem in the chassis, it should be stopped immediately and handed over to a professional maintenance personnel for diagnosis and repair.