Basically, capacitors are components that store charge, a bit like a mobile battery, but not much charge. Capacitors can store that charge and then, release it very quickly. Capacitors are mainly use to solve problems like the instability of a circuit or unwanted noise, also serves as a filter in the series of switching and decoupling.
When DC voltage reaches a capacitor, no current flows, but the capacitor charges itself like a little battery. The positive and negative charges are equal and opposite.
You can imagine positive "charge particles" accumulating on one side of the capacitor and attracting negative "charge particles" to the opposite side. In most modern electrolytic capacitors, the plates have been reduced to two strips of very thin, flexible, metallic film, often wrapped around each other, separated by an equally thin insulator. Disc ceramic capacitors typically consist of just a single disc of nonconductive material with metal painted on both sides and leads soldered on
The two most common varieties of capacitors are ceramic (capable of storing a relatively small charge) and electrolytic (which can be much larger). Ceramics are often disc-shaped and yellow in color; electrolytic are often shaped like miniature tin cans and may be just about any color. Ceramic capacitors have no polarity, meaning that you can apply negative voltage to either side of them. Electrolytic do have polarity, and won’t work unless you connect them the right way around. The schematic symbol for a capacitor has two significant variants: with two straight lines (symbolizing the plates inside a capacitor), or with one straight line and one curved line, as shown in next photo. When you see a curved line, that side of the capacitor should be more negative than the other. The schematic symbol may also include a + sign
SMD Ceramic type Works as a filter noose, if we are pay attention to symbols & shapes. Ceramic type components have no poles, so the installation may be reversed. Often we find on the 19V input bypass path in all circuit systems and one of the causes of the most dominant motherboard short circuit (this type of component often suffered damage, especially in the case of short circuit).
The below type of capacitor is called Electrolytic. Its storage capacity, known as capacitance, is 470µF, but I’ll explain that in a moment. 50V is its maximum voltage.
The short lead is the negative side, also identified with minus signs. Never connect an electrolytic capacitor to a power supply the wrong way around, electrolytic capacitors exhibit polarity. You should connect the (+) pin to the side that current is coming from. Capacitance is measured in farads, abbreviated with letter F. But a 1F capacitor is very large, abbreviated µF.
The µ symbol is the Greek letter mu, but often µF is printed as uF. There are 1,000,000 microfarads in 1 farad, 1,000 nanofarads (nF) in 1 microfarad, and 1,000 picofarads (pF) in 1 nanofarad. The weakness of electrolytic capacitor is the leakage of components that causes the value of the output voltage to change drop, even short circuit is often found on the problem of 3V and 5V circuits as well VCC core. SMD Tantalum in addition to its function as temporary load storage. In the laptop motherboard also it functions as a filter in switching and decoupling circuits.
If we look at the symbols and shapes, the components of Elco and tantalum have positive and negative poles, so the installation on the circuit should not be inverted. (Elco may be replaced with tantalum vice versa). This type of component is widely used for alternate NEC/TOKIN replacement on the VCC core in case of no display, with the characteristic of no display total voltage VCC core drop 0v - 0.9V. It should be noted that NEC/TOKIN is also included in component capacitor families.
The picture on the above, the bipolar capacitor component is arranged in parallel and connected directly to the VIN (source voltage of the circuit system) and on the foot after it is connected to ground. And what happens if this component is damaged/short? Then all VIN lines in all systems will be affected by short.
The techniques to find a shorting capacitor arranged parallel as in the picture above, remove the capacitor one by one. Parallel arranged capacitors serve to flatten currents and voltages (currents and voltages are always directly proportional).
The basic principle of capacitor is the charge storage and then releases it. While the capacitors are arranged in series then the characteristic will be different, if the input voltage goes up he fills the charge and if the voltage drops he will dispose of the charge.
The capacitor will conduct electricity when the input is off or in AC mode and charge if ON or when in the DC mode, there are 2 functions the first function to block the DC voltage and the second function to smooth the AC voltage.
The black probe does not always have to be on the ground pin of the capacitor, can be in the screw hole or any part as long as it is safe and is a ground path.
Motherboard will get +DCIN once insert adapter as following circuit below:
19V will be passing through capacitor PC6 which could make the current become more stable, if there is 19V exit on PC6 you can be sure there's no problem with capacitor but if there is no voltage it can be sure the capacitor is broken.
Capacitor measurement without voltage:
Turn the dial to the buzzer mode, for a correct measurement and connect the test leads to the capacitor terminals. Note that electrolytic capacitors (most commonly shaped like cans) are polarized, so identify the positive and negative terminals before you connect the multimeter's leads. This may not matter much for your test. Sometimes you need to remove the capacitor from the circuit.
Capacitor basics:
DC current does not flow through a capacitor, but voltage can accumulate very quickly inside it, and remains after the power supply is disconnected. Next photos below may help to give you an idea of what happens inside a capacitor when it is fully charged.When DC voltage reaches a capacitor, no current flows, but the capacitor charges itself like a little battery. The positive and negative charges are equal and opposite.
You can imagine positive "charge particles" accumulating on one side of the capacitor and attracting negative "charge particles" to the opposite side. In most modern electrolytic capacitors, the plates have been reduced to two strips of very thin, flexible, metallic film, often wrapped around each other, separated by an equally thin insulator. Disc ceramic capacitors typically consist of just a single disc of nonconductive material with metal painted on both sides and leads soldered on
The two most common varieties of capacitors are ceramic (capable of storing a relatively small charge) and electrolytic (which can be much larger). Ceramics are often disc-shaped and yellow in color; electrolytic are often shaped like miniature tin cans and may be just about any color. Ceramic capacitors have no polarity, meaning that you can apply negative voltage to either side of them. Electrolytic do have polarity, and won’t work unless you connect them the right way around. The schematic symbol for a capacitor has two significant variants: with two straight lines (symbolizing the plates inside a capacitor), or with one straight line and one curved line, as shown in next photo. When you see a curved line, that side of the capacitor should be more negative than the other. The schematic symbol may also include a + sign
SMD Ceramic type Works as a filter noose, if we are pay attention to symbols & shapes. Ceramic type components have no poles, so the installation may be reversed. Often we find on the 19V input bypass path in all circuit systems and one of the causes of the most dominant motherboard short circuit (this type of component often suffered damage, especially in the case of short circuit).
The below type of capacitor is called Electrolytic. Its storage capacity, known as capacitance, is 470µF, but I’ll explain that in a moment. 50V is its maximum voltage.
The short lead is the negative side, also identified with minus signs. Never connect an electrolytic capacitor to a power supply the wrong way around, electrolytic capacitors exhibit polarity. You should connect the (+) pin to the side that current is coming from. Capacitance is measured in farads, abbreviated with letter F. But a 1F capacitor is very large, abbreviated µF.
The µ symbol is the Greek letter mu, but often µF is printed as uF. There are 1,000,000 microfarads in 1 farad, 1,000 nanofarads (nF) in 1 microfarad, and 1,000 picofarads (pF) in 1 nanofarad. The weakness of electrolytic capacitor is the leakage of components that causes the value of the output voltage to change drop, even short circuit is often found on the problem of 3V and 5V circuits as well VCC core. SMD Tantalum in addition to its function as temporary load storage. In the laptop motherboard also it functions as a filter in switching and decoupling circuits.
If we look at the symbols and shapes, the components of Elco and tantalum have positive and negative poles, so the installation on the circuit should not be inverted. (Elco may be replaced with tantalum vice versa). This type of component is widely used for alternate NEC/TOKIN replacement on the VCC core in case of no display, with the characteristic of no display total voltage VCC core drop 0v - 0.9V. It should be noted that NEC/TOKIN is also included in component capacitor families.
Capacitors in the Circuit:
The picture on the above, the bipolar capacitor component is arranged in parallel and connected directly to the VIN (source voltage of the circuit system) and on the foot after it is connected to ground. And what happens if this component is damaged/short? Then all VIN lines in all systems will be affected by short.
The techniques to find a shorting capacitor arranged parallel as in the picture above, remove the capacitor one by one. Parallel arranged capacitors serve to flatten currents and voltages (currents and voltages are always directly proportional).
The basic principle of capacitor is the charge storage and then releases it. While the capacitors are arranged in series then the characteristic will be different, if the input voltage goes up he fills the charge and if the voltage drops he will dispose of the charge.
The capacitor will conduct electricity when the input is off or in AC mode and charge if ON or when in the DC mode, there are 2 functions the first function to block the DC voltage and the second function to smooth the AC voltage.
How to measure capacitance:
The black probe does not always have to be on the ground pin of the capacitor, can be in the screw hole or any part as long as it is safe and is a ground path.
Capacitor measurement using voltage:
We take circuit below for understand how you can test the SMD capacitor, voltage measurement techniques pay attention to the position of the probe. The black probe is on ground (GND) while the red probe is also up to which point we want to test (input or output) this measurement method is used to ensure the uninterrupted voltage after passing through the components that carry the voltage.Motherboard will get +DCIN once insert adapter as following circuit below:
19V will be passing through capacitor PC6 which could make the current become more stable, if there is 19V exit on PC6 you can be sure there's no problem with capacitor but if there is no voltage it can be sure the capacitor is broken.
Capacitor measurement without voltage:
Turn the dial to the buzzer mode, for a correct measurement and connect the test leads to the capacitor terminals. Note that electrolytic capacitors (most commonly shaped like cans) are polarized, so identify the positive and negative terminals before you connect the multimeter's leads. This may not matter much for your test. Sometimes you need to remove the capacitor from the circuit.
