Where is the power supply unit in the laptop

Reasons why the power supply does not work

Below is a list of why the power supply is not working, shuts down under load, or turns on and off immediately.

  • Age: Most power supplies last 5 to 10 years, however this is not a warranty age. The duration of the power supply depends on how often you use your computer.
  • Electrical problems (lightning, power surges, etc.).
  • Dirt / foreign matter (cigarette smoke, house dust, etc.).
  • Voltage drop: intentional or unintentional voltage drop.
  • Overheating and / or poor ventilation.

The most common reasons why power supplies are not working are overheating and lightning. However, if you are a cigarette smoker or your computer is in a dusty environment, it is possible that the power supply will not work until the end of its warranty age.

power, supply, unit, laptop

Power supply in the computer

What is a power supply?

A computer power supply is a device that converts alternating current (electricity from your wall outlet, typically 220V) into direct current to power the rest of the components inside the computer case. Externally, the power supply is a three-pin plug that plugs into an outlet.

Power supply on a MacBook laptop

Power supplies are different. Some of them (usually for laptops) have 65W output, while others can output 1000W or more. Some may only have 10 amps while others have 65 amps.

When the power supply is not able to provide enough power to power the computer, various problems occur in the operation of the device, such as freezes, reboots, errors, or shutdowns.

Power supply on laptop

Symptoms of a faulty power supply

Most often, it is simply impossible to determine the malfunction of the power supply. However, there are several symptoms that indicate a possible problem.

  • Strange noise coming from the back of the computer where the cord is located. The power supply beeps and does not turn on.
  • When the computer is turned on, nothing happens. This can sometimes coincide with a blinking LED on the front of the computer or an LED on the back of the power supply (if any).
  • The power supply turns on and off immediately. It could also be caused by a power problem. Also, it could indicate a problem with the motherboard.
  • The computer works for a while, but when you start a game or other program, it turns off without warning. Also you can get blue screen of death.

If we are talking about games, you should know that modern video cards consume a lot of power and amperes. Thus, you should make sure that the power supply has enough power to operate the hardware inside your computer, especially the graphics card.

The power supply does not work: causes, symptoms and what to do?

Sooner or later, any power supply on your computer stops working. In this article, we will find out what may be the cause of a malfunctioning power supply, how to check if the power supply is working on a computer, what to do to avoid damage to the power supply.

How to make the power supply last longer?

There are several rules that you must adhere to in order for the power supply to work for as long as possible.

  • The power supply should not be operating at full capacity. In other words, the power of the power supply must be at least 20% higher than what the computer needs.
  • Don’t skimp on buying a power supply. A good PSU will cost a little more, but it will last much longer.
  • Keep the area around the power supply clean. Clean the computer and the entire room from dust regularly.
  • The temperature of the power supply and the rest of the computer equipment should not exceed 80 degrees.
  • Install good ventilation in your computer. The computer must “breathe”, otherwise it will overheat and die.

You can also watch a video to check if the computer’s power supply is working.

That’s all! We have covered the most common reasons why the power supply does not work, the symptoms, and what to do to prolong the life of the power supply.

Where is the BIOS battery on acer laptop

For many computer users, it comes as a complete surprise to the need to periodically change the battery located in the BIOS chip. Consider if there is a BIOS battery in a laptop and if so, how to change it.

How to turn on battery charging in a laptop

It happens that, due to incorrect operation of the BIOS, the laptop battery does not charge. In this case, they act like this:

  • Entering the BIOS settings, they set the default parameters. To do this, select the item “Load defaults”, “Load optimized BIOS defaults” or something similar.
  • Find an updated BIOS version on the laptop manufacturer’s website. With a high probability, flaws in it have already been eliminated.
  • Install the update, acting strictly according to the attached instructions (text file).

If manipulating the BIOS did not help, check for other possible causes.

BIOS activation

After replacing the battery and assembling the laptop, they turn it on and enter the BIOS settings. By operating the navigation keys and “Enter”, go through the menu items and restore user settings in accordance with the entries.

Some items are expanded by pressing “Enter”. For example, if you hover over the “Boot priority” item and press “Enter”, a submenu will open:

After selecting the main boot device (it will be signed as “First Boot Device”), the user presses “Enter” and returns to the menu. After specifying the settings, go to the “Save Exit” menu item, as a result of which the settings are saved and the PC starts loading the OS.

Signs of a defective battery

The depletion of the charge leads to the following consequences:

  • Windows displays a message like “CMOS Battery Low”.
  • All user settings are reset, incl. date and time. The latter entails malfunctions of antiviruses and other software with a limited license validity period (keys “fly off”), the appearance in the browser of messages about the absence of site certificates, the termination of automatic updating of the operating system and other programs.
  • Many laptops won’t turn on or freeze when the Windows logo appears.

Operating a PC with a discharged battery sometimes leads to BIOS problems.

SNS System Watch Freelance reporter

Yes, it is not so secret. But we will definitely publish it if everything works out. And I will attach a photo for different versions. There are really a lot of laptops and each has its own “wisdom”.

The manufacturers hide these secret places very well.

Added after 2 minutes 40 seconds

Battery expert advice

In order to extend the life of the battery, proceed as follows:

  • The battery is “pumped over” immediately after purchase and thereafter annually: it is fully charged three times (charge limitation is previously removed) and discharged. The new battery is used during the “pumping” in a sparing mode (do not start video players and other resource-intensive applications).
  • The rest of the time, the charge limit is set: by 80%. if the PC often works offline and by 50% when working from the network.
  • Mains powered whenever possible: battery life is determined by the number of charge / discharge cycles.
  • Unplug a non-working laptop from the mains, unless you need to charge the battery.
  • Do not leave the battery in a discharged state for a long time.
  • In the power settings (right-clicking on the battery icon in the system tray), the optimal parameters are set (depending on the nature of the work of this user).
  • Eliminate the complete discharge of the battery (you cannot leave the PC turned on or in standby mode for a long time).

By adhering to the described rules, the user will ensure a long and trouble-free operation of his laptop.

I have a laptop, most of the time I work from the mains.
I know about the battery, and they also say that there is still some kind of battery inside the laptop.

If the BIOS battery is out of order, there is no harm to the laptop hardware from this.
But with the software part, sometimes problems happen.

This often affects programs with a limited license period, for example, antivirus systems.
After a failure of the system time and date, such programs may not load, work incorrectly, or will not be updated.

However, replacing the internal battery in a laptop is more difficult than in a desktop PC.

The way to replace the BIOS battery depends on:
– from motherboard design,
– from the building structure,
– on the way it is installed on the motherboard.

The battery itself may look different in different laptop models.

There are various options for the location of the battery:

The battery is easily accessible, located under the cover near the RAM, removed and installed in the seat without additional tools.

The battery is easily accessible, but to replace it, you need to solder the contact wires.

To access the battery, you need to completely disassemble the laptop case and work with a soldering iron to replace it.

Usually it is necessary to disassemble the laptop, open the removable panel and remove the battery, which is located under the tape or foil.
Foil protects the battery from fire and contact with other components.

SNS-amigo, It’s hard to say that you know such a secret there, but still we have a forum and try to disclose your secret knowledge so that they become known to everyone, because there are a lot of laptop owners.

goredey, we never found out if the beech POST passes.

Power supply specifications

Consider the device metrics that would influence your purchasing choices!
Feeder manufacturer. it is recommended to purchase only well-known and well-established brands. Speaking of computers in Russian. buy proven devices! Little-known manufacturers who have not proven themselves in the sales market, and even more so the Chinese range should be completely excluded. Buying a device to power your PC according to the destination. Powerful devices need to be bought if you are a gamer and you need a lot of computer resources to play games. Basically, for everything else, a 300-400 W power supply is suitable. In addition, a device that is too strong will work idle, without fully revealing itself.

The ability to generate the voltage required at the thresholds of your system’s performance standards. Quality that determines the stability of the system operation of your computer

Noise level is a very important criterion when buying a device. When the power supply heats up, the cooling fans are automatically turned on, the function of which is to remove hot air outside the system unit and cool the unit itself. The number of coolers (fans) and their rotation speed can be completely different, it all depends on the model. The speed of the coolers can be constant, or vary depending on the operating conditions of the device we are considering. Accordingly, all these characteristics will directly affect the level of noise produced.!

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There is also a separate type of power supply devices for the system unit, the so-called without a device without a fan, with passive cooling. But the indicators of the produced capacity of such units are very limited.!

The main problems and breakdowns of computer power systems

Like all the working components of your system, the node that is responsible for receiving power can also fail. The main and most pressing problem is the failure of electrolytic capacitors, which have such a feature as “boil” and “swell”, or bother us in other ways. The main factors in the occurrence of which our unit can fail and what consequences this can have for the entire computer system are the main weakness of the power supply, power surges in the network, which are the cause of the breakdown, and the main one. Well, if this impulse has passed the filters of the power supply device, then this can damage the rest of the system unit components! Therefore, when buying, make sure that the power supply unit contains the required number of high-quality filters to prevent such incidents.!

Where is the power supply unit in the computer

A personal computer power supply is a device that converts the alternating current of your network into 220 volts, into direct current of different voltages, depending on the layout of the computer nodes. Many indicators of the operation of your system depend on the high-quality assembly and operation of this unit. Where is the power supply in the computer. mainly in the slot of the system box, in the back upper part. There are models where the location of this power conversion installation is in a different place, but this is rather an exception to the rule.

How to change the power supply in the computer

This arrangement allows this power supply to act as a heat sink to cool the PC case thanks to its built-in fans.

Different types of power supplies for your hardware have different output voltages, depending on the model. In modern devices, this is 12; 5 and 3.3 volts, as well as such an indicator as power is very important. For example. at the indicator specified by the manufacturer of 400 W, the power consumption is much higher, which, as it were, gives a certain margin of safety for the power supply.

How to replace a computer’s power supply

We will tell you how to do this in Russian, in a simple and accessible language! consider the case when you need to replace an old device with a new one. Perhaps it is outdated or does not suit you in terms of noise level. Either the model does not satisfy. And so how to change the power supply on the computer:

  • completely de-energize the device;
  • we carry the system unit to a well-lit place;
  • unscrew the fixing bolts, remove the box cover. Remember the connection locations of all cords and cables of your device before disconnecting them.!
  • take out the old power supply unit and install a new one in the vacant socket;
  • we connect the cables and cords of the installed device to the corresponding connectors, do not forget that the motherboard is connected by two cords from the power device;
  • check the computer for working capacity by turning on.

As you can see, despite the complexity of the characteristics of the device in question, its independent replacement should not cause any problems! Having basic knowledge in the structure of the system unit, you can easily complete the task! Well, if you are absolutely not familiar with the filling of the system device, there are many training videos on this topic.!

Where is the power supply in the system unit

Hello everyone! Today there will be a small “introduction” “computer power supply”. In this note, we will talk about where the computer power supply unit (PSU) is located and what it is needed for, we will also analyze where and with what the computer PSU is connected.

As the name implies, the power supply unit must “power”. ie. ensure the supply of electricity to all components inside the computer system unit. To see how it looks, and most importantly. where it is located, you need to open the system unit and actually see what and where is inside.

The PSU can be located both above and below. in different models of the case of the system unit in different ways. However, now on sale more and more cases began to be found with the lower location of the power supply unit. What is the reason, honestly, I don’t know.

The power supply itself visually resembles a small box, which has a fan on the back or on any other side, which is effective, or may not be very efficient, but nevertheless cools the entire structure. The fan diameter can be completely different from model to model, usually in the range of 40-140 mm.

The power supply unit is connected to a regular network (220 Volts) on the one hand, and on the other, to the computer motherboard, on which there is a connector specially designed for this business. Through this connector, the motherboard is “powered”, which means all those components that are connected to it (some components require additional power, since the power from the connectors of the motherboard is not enough for them).

The interface for connecting the power supply unit is ordinary wires. At the ends of the wires there are connectors for connecting devices (accessories). As mentioned above, one wire goes to the motherboard, the number of the rest depends on the power of the PSU itself and its cost.

The power of a computer’s power supply is one of its most important characteristics. And you can calculate it in several ways. Here are two main ones. using the online service “online calculator for calculating the power of the power supply”, or manually. simply by calculating the power consumption of each of the components of your PC. However, in the “manual” method there are a number of disadvantages, and you need to have some experience in all this, because there are many subtleties, without which there will be a large error in the calculations.

In most cases, when the computer does not turn on, the cause of the breakdown is a faulty power supply, which could have failed due to power outages or overload.

A computer power supply is a very important component of a computer, thanks to which not only the motherboard is powered, but also most other components. The power supply supplies power to: hard drive, CD, DVD drives, Floppy drive, some video cards. All of the above components are connected not only to the motherboard, they are connected to the power supply using special connectors.

Let’s consider a case when it is necessary to replace an old power supply with a new one. By the way, the power supply is changed not only when it burns out, perhaps the old unit simply does not have enough power to pull all the components of your computer.

As practice shows, not everyone knows what a power supply looks like, so I show a photo of an average power supply:

Now about where the power supply is attached. If you look at the system unit from the back, then the part where the power cable is inserted is the unit. As you can see, it is mounted on four bolts, which are unscrewed with an ordinary Phillips screwdriver.

If you remove the side cover of the system unit, then the place for the power supply looks like this:

As you can see from the photo above, cables of different connectors leave the unit and are connected to the accessories.

Well, now in order. In order to replace or reinstall the power supply, you must do the following:

Unplug the system unit from the outlet and disconnect all cords from it.

Move the system unit to a place convenient for you with good lighting.

After the new unit is available to you, you can start disconnecting the old one, but before that, remember well which wire and where it is connected. If necessary, sketch the diagram, or better yet, take a picture with a camera. This is done in order to then connect a new power supply in the same way.

Disconnect all cables of the old unit from the motherboard and accessories.

Holding the power supply with one hand, unscrew the fastening bolts with a screwdriver with the other.

Insert and screw on the new power supply. Following the sketched diagram, connect all cables to the appropriate connectors.

Please note that the motherboard can be connected with two cables from the power supply

It should also be noted that old and new hard drives are connected using different plugs. New SATA hard drives are connected using cables of the same name:

Old-style hard drives are connected in the same way as floppy drives:

After everything is connected, close the lid of the system unit and connect the necessary devices. Try turning on your computer.

In most cases, when the computer does not turn on, the cause of the breakdown is a faulty power supply, which could have failed due to power outages or overload.

A computer power supply is a very important component of a computer, thanks to which not only the motherboard is powered, but also most other components. The power supply supplies power to: hard drive, CD, DVD drives, Floppy drive, some video cards. All of the above components are connected not only to the motherboard, they are connected to the power supply using special connectors.

Let’s consider a case when it is necessary to replace an old power supply with a new one. By the way, the power supply is changed not only when it burns out, perhaps the old unit simply does not have enough power to pull all the components of your computer.

As practice shows, not everyone knows what a power supply looks like, so I show a photo of an average power supply:

Now about where the power supply is attached. If you look at the system unit from the back, then the part where the power cable is inserted is the unit. As you can see, it is mounted on four bolts, which are unscrewed with an ordinary Phillips screwdriver.

If you remove the side cover of the system unit, then the place for the power supply looks like this:

As you can see from the photo above, cables of different connectors leave the unit and are connected to the accessories.

Well, now in order. In order to replace or reinstall the power supply, you must do the following:

Unplug the system unit from the outlet and disconnect all cords from it.

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Move the system unit to a place convenient for you with good lighting.

After the new unit is available to you, you can start disconnecting the old one, but before that, remember well which wire and where it is connected. If necessary, sketch the diagram, or better yet, take a picture with a camera. This is done in order to then connect a new power supply in the same way.

Disconnect all cables of the old unit from the motherboard and accessories.

Holding the power supply with one hand, unscrew the fastening bolts with a screwdriver with the other.

Insert and screw on the new power supply. Following the sketched diagram, connect all cables to the appropriate connectors.

Please note that the motherboard can be connected with two cables from the power supply

It should also be noted that old and new hard drives are connected using different plugs. New SATA hard drives are connected using cables of the same name:

Old-style hard drives are connected in the same way as floppy drives:

After everything is connected, close the lid of the system unit and connect the necessary devices. Try turning on your computer.

How to replace (install) a computer power supply

In most cases, when the computer does not turn on, the cause of the breakdown is a faulty power supply, which could have failed due to power outages or overload.

A computer power supply is a very important component of a computer, thanks to which not only the motherboard is powered, but also most other components. The power supply supplies power to: hard drive, CD, DVD drives, Floppy drive, some video cards. All of the above components are connected not only to the motherboard, they are connected to the power supply using special connectors.

Let’s consider a case when it is necessary to replace an old power supply with a new one. By the way, the power supply is changed not only when it burns out, perhaps the old unit simply does not have enough power to pull all the components of your computer.

As practice shows, not everyone knows what a power supply looks like, so I show a photo of an average power supply:

Now about where the power supply is attached. If you look at the system unit from the back, then the part where the power cable is inserted is the unit. As you can see, it is mounted on four bolts, which are unscrewed with an ordinary Phillips screwdriver.

If you remove the side cover of the system unit, then the place for the power supply looks like this:

As you can see from the photo above, cables of different connectors leave the unit and are connected to the accessories.

Well, now in order. In order to replace or reinstall the power supply, you must do the following:

Unplug the system unit from the outlet and disconnect all cords from it.

Move the system unit to a place convenient for you with good lighting.

After the new unit is available to you, you can start disconnecting the old one, but before that, remember well which wire and where it is connected. If necessary, sketch the diagram, or better yet, take a picture with a camera. This is done in order to then connect a new power supply in the same way.

Disconnect all cables of the old unit from the motherboard and accessories.

Holding the power supply with one hand, unscrew the fastening bolts with a screwdriver with the other.

Insert and screw on the new power supply. Following the sketched diagram, connect all cables to the appropriate connectors.

Please note that the motherboard can be connected with two cables from the power supply

It should also be noted that old and new hard drives are connected using different plugs. New SATA hard drives are connected using cables of the same name:

Old-style hard drives are connected in the same way as floppy drives:

After everything is connected, close the lid of the system unit and connect the necessary devices. Try turning on your computer.

How to check a laptop power supply: 3 main ways

We came to a cafe, took out a laptop to show our friends vacation photos. An unpleasant surprise: the laptop does not turn on, although it was charged for several hours. Does the situation sound familiar? The first thought is that the laptop is broken. Don’t jump to conclusions, check your laptop charger. We will tell you how to do this, and computer professionals. experts of the Batterion company will help us.

What breaks in the charger. visual inspection

A damaged connector is the most common cause of adapter failure. The plug itself or the socket in the laptop may break. The plug is dangling in the connector, the wires are bare, the connector is cracked. you cannot use the power supply, you need to repair or replace a part.

The queue reached the “black box”. the power supply unit. You can even smell it: you hear the smell of burnt wiring or plastic. it’s bad. And if you see melting on the case, it is better to immediately look for a new laptop charger. Repair in this case is impractical, say the computer experts. Batterion specialists will help you choose a high-quality device that is 100% suitable for your laptop.

What does a laptop charger consist of?

Before checking the adapter, you need to find out what elements it consists of. Components of the charger:

  • Cable with a plug (plugged into a socket).
  • The power supply is the “heart” of the charger. Electronic “filling” packed in a rectangular plastic case.
  • Cord with connector (plugged into the laptop connector).

If at least one of the elements is damaged, the charger will fail or will not work correctly.

The laptop won’t charge: look for the real reason

First you need to exclude extraneous reasons, perhaps the power supply has nothing to do with it.

First, check the voltage and serviceability of the outlet. To do this, you need to turn on an accurately working device (table lamp, hairdryer, mobile phone) into the network. Another option is to plug the laptop into a different, definitely working outlet. Voltage. 220V and the outlet is in order. go ahead.

Remove the battery from the laptop and connect the power supply to the mains and turn on the laptop. The computer is working, the indicator on the taskbar shows the operation of the mains, which means that the charger is in order. Battery problem. If the laptop does not charge through the adapter, proceed to inspect this device.

How to check the power supply with a multimeter:

  • Connect the charger to the mains.
  • Connect the tester terminals to the connector. Insert the red wire into the plug, and attach the black wire with a metal tip from above. The power supply is definitely faulty when the voltage on the multimeter screen does not stabilize, constantly deviating to the side by 2-3 Volts. In this case, experts definitely advise replacing the device.
  • Another option: the tester does not show voltage at all. So, you need to check the cord. it does not supply current to the power supply. Switch the multimeter to special mode, attach the terminals to the opposite ends of the cable. Heard a sound signal. the wire is working properly. Silence in response indicates damage to the contacts inside the cable. Change the cord. it’s cheaper than a new laptop charger.

You need to carry out diagnostics as soon as possible, because lithium-ion batteries cannot be in a discharged state for a long time. Only 10-14 days of forced “idle time” of an empty battery, and it can be thrown away. the capacity is irretrievably lost. Do not want to spend money on a new battery. urgently solve problems with the power supply.

Adapter, battery and keyboard. these are the most common laptop parts that fail. You need a high-quality replacement of components for your laptop. contact the professionals! A careful attitude to the laptop, competent diagnostics and prompt problem solving are the main conditions for a long laptop operation!

The laptop power supply is not working. How to fix?

An ordinary laptop power supply is a very compact and rather powerful switching power supply.

In the event of a malfunction, many simply throw it away, and buy a universal power supply unit for laptops for replacement, the cost of which starts from 1000 rubles. But in most cases, you can fix such a block with your own hands.

It’s about repairing a power supply from an ASUS laptop. It is also an AC / DC power adapter. Model ADP-90CD. Output voltage 19V, maximum load current 4.74A.

There was no break in the connecting wires or breakage of the plug. But when the power supply was connected to the laptop, the battery did not start charging, and the green indicator on its case went out and glowed at half the original brightness.

It was also heard that the unit beeps. It became clear that the switching power supply was trying to start, but for some reason, either an overload or short-circuit protection was triggered.

A few words about how you can open the case of such a power supply. It’s no secret that it is made sealed, and the design itself does not imply disassembly. For this we need several tools.

We take a manual jigsaw or a canvas from it. It is better to take the canvas on metal with a fine tooth. The power supply itself is best clamped in a vice. If they are not there, then you can contrive and do without them.

Then, with a manual jigsaw, we cut into the depth of the body by 2-3 mm. in the middle of the body along the connecting seam. The cut must be done carefully. If you overdo it, you can damage the circuit board or electronic filling.

Then we take a flat screwdriver with a wide edge, insert it into the cut and unclip the halves of the case. There is no need to rush. When separating the halves of the case, a characteristic click should occur.

After the power supply case is opened, we remove the plastic dust with a brush or a brush, we take out the electronic filling.

To inspect the elements on the printed circuit board, you will need to remove the aluminum radiator bar. In my case, the bar was attached to other parts of the radiator with latches, and was also glued to the transformer with some kind of silicone sealant. I managed to separate the bar from the transformer with a sharp blade of a knife.

The photo shows the electronic filling of our block.

The fault itself did not take long to look for. Even before opening the case, I did test turns. After a couple of connections to the 220V network, something crackled inside the unit and the green indicator indicating work was completely extinguished.

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When inspecting the case, a liquid electrolyte was found, which leaked into the gap between the network connector and the elements of the case. It became clear that the power supply unit ceased to function normally due to the fact that the electrolytic capacitor 120 uF 420V “slammed” due to exceeding the operating voltage in the 220V power grid. Quite an ordinary and widespread malfunction.

When the capacitor was dismantled, its outer shell crumbled. Apparently lost its properties due to prolonged heating.

The safety valve in the upper part of the housing is “swollen”. this is a sure sign of a faulty capacitor.

Here’s another example with a faulty capacitor. This is a different laptop power adapter. Pay attention to the protective notch on the top of the condenser housing. She broke open from the pressure of the boiling electrolyte.

In most cases, bringing the PSU back to life is pretty easy. First you need to replace the main culprit of the breakdown.

At that time, I had two suitable capacitors at hand. I decided not to install the SAMWHA 82 uF 450V capacitor, although it was ideally sized.

The fact is that its maximum operating temperature is 85 0 C. It is indicated on its body. And if the Honor has a compact and unventilated PSU case, the temperature inside it can be very high.

Long-term heating has a very bad effect on the reliability of electrolytic capacitors. Therefore, I installed a Jamicon capacitor with a capacity of 68 μF 450V, which is designed for operating temperatures up to 105 0 С.

It costs Honor that the capacity of the native capacitor is 120 uF, and the operating voltage is 420V. But I had to put a capacitor with a smaller capacity.

In the process of repairing laptop power supplies, I encountered the fact that it is very difficult to find a replacement for the capacitor. And the point is not at all in capacity or operating voltage, but in its dimensions.

Finding a suitable capacitor that would fit into a cramped case proved to be a daunting task. Therefore, it was decided to install a product of suitable size, albeit a smaller capacity. The main thing is that the capacitor itself is new, of high quality and with an operating voltage of at least 420

450V. As it turned out, even with such capacitors, the power supplies work properly.

When sealing a new electrolytic capacitor, the polarity of the terminals must be strictly observed! Typically, there is a “” or “-” sign next to the hole on the PCB. In addition, a minus can be marked with a black bold line or a mark in the form of a spot.

On the capacitor case on the negative side there is a mark in the form of a strip with a minus sign “-“.

When turning on for the first time after repair, keep a distance from the power supply, because if the polarity of the connection is reversed, the capacitor will “pop” again. This can cause the electrolyte to get into the eyes. This is extremely dangerous! Wear protective goggles if possible.

And now I’ll tell you about the “rake” that it is better not to step on.

Before you change anything, you need to thoroughly clean the board and circuit elements from liquid electrolyte. This is not a pleasant occupation.

The fact is that when an electrolytic capacitor slams, the electrolyte inside it breaks out under great pressure in the form of splashes and steam. He, in turn, instantly condenses on the nearby parts, as well as on the elements of the aluminum radiator.

Since the installation of the elements is very tight, and the case itself is small, the electrolyte gets into the most inaccessible places.

Of course, you can cheat, and not clean out all the electrolyte, but this is fraught with problems. The trick is that the electrolyte conducts electric current well. I was convinced of this from my own experience. And although I cleaned the power supply very carefully, I did not begin to solder the choke and clean the surface under it, I hurried.

As a result, after the power supply was assembled and connected to the mains, it worked properly. But after a minute or two, something crackled inside the case, and the power indicator went out.

After opening it, it turned out that the remaining electrolyte under the throttle closed the circuit. Because of this, the T3.15A 250V fuse on the 220V input circuit has blown. In addition, in the place of the short circuit, everything was covered with soot, and the wire of the choke burned out, which connected its screen and the common wire on the printed circuit board.

The same choke. Burned-out wire restored.

Soot from a short circuit on the PCB directly under the choke.

The first time I replaced the fuse with a new one from a similar power supply. But when it burned down a second time, I decided to restore it. This is what the fuse on the board looks like.

And this is what he has inside. He himself can be easily disassembled, you just need to squeeze the latches at the bottom of the case and remove the cover.

To restore it, you need to remove the remnants of the burnt wire and the remnants of the insulating tube. Take a thin wire and solder it in place of your own. Then collect the fuse.

Someone will say that this is a “bug”. But I disagree. In the event of a short circuit, the thinnest wire in the circuit burns out. Sometimes even the copper tracks on the PCB burn out. So in which case our self-made fuse will do its job. Of course, you can also do with a thin wire jumper by soldering it to the contact dimes on the board.

In some cases, in order to clean out all the electrolyte, it may be necessary to dismantle the cooling radiators, and with them active elements such as MOSFETs and dual diodes.

As you can see, liquid electrolyte can also remain under coil products, such as chokes. Even if it dries out, then in the future because of it, corrosion of the leads may begin. A good example is in front of you. Due to electrolyte residues, one of the capacitor leads in the input filter completely corroded and fell off. This is one of the laptop power adapters that I have been repaired.

Let’s go back to our power supply. After cleaning from electrolyte residues and replacing the capacitor, you must check it without connecting it to a laptop. Measure the output voltage at the output plug. If everything is in order, then we assemble the power adapter.

I must say that this is a very time-consuming business. First.

The PSU cooling heatsink consists of multiple aluminum fins. Between themselves, they are fastened with latches, and are also glued with something resembling a silicone sealant. It can be removed with a penknife.

The upper radiator cover is fastened to the main part with latches.

The bottom plate of the heatsink is fixed to the PCB by soldering, usually in one or two places. A plastic insulating plate is placed between it and the PCB.

A few words about how to fasten the two halves of the body, which at the very beginning we sawed with a jigsaw.

In the simplest case, you can simply assemble the power supply and wrap the halves of the case with electrical tape. But this is not the best option.

I used hot melt glue to glue the two plastic halves together. Since I don’t have a thermo gun, I cut off pieces of hot melt glue from the tube with a knife and put them in the grooves. After that, I took a hot air soldering station, set about 200 degrees

250 0 C. Then he heated pieces of hot glue with a hair dryer until they melted. I removed the excess glue with a toothpick and once again blew it with a hairdryer on the soldering station.

It is advisable not to overheat the plastic and generally avoid excessive heating of foreign parts. For me, for example, the plastic of the case began to brighten with strong heating.

Despite this, it turned out very soundly.

Now I will say a few words about other malfunctions.

In addition to such simple breakdowns as a slammed capacitor or an open in the connecting wires, there are also such as an open circuit in the choke output in the line filter circuit. Here is a photo.

It would seem that the matter is trifling, I rewound the coil and sealed it into place. But it takes a lot of time to find such a malfunction. It is not possible to detect it immediately.

Surely you have already noticed that large-sized elements, like the same electrolytic capacitor, filter chokes and some other parts, are smeared with something like white sealant. It would seem, why is it needed? And now it is clear that with its help large parts are fixed, which can fall off from shaking and vibrations, like this very choke, which is shown in the photo.

By the way, initially it was not securely fixed. I chatted. chatted, and fell off, taking the life of another power supply from the laptop.

I suspect that thousands of compact and rather powerful power supplies are sent to the landfill from such banal breakdowns.!

For a radio amateur, such a pulsed power supply with an output voltage of 19.20 volts and a load current of 3-4 amperes is just a godsend! Not only is it very compact, but also quite powerful. Typically, the wattage of power adapters is 40

Unfortunately, in case of more serious malfunctions, such as the failure of electronic components on the printed circuit board, the repair is complicated by the fact that it is quite difficult to find a replacement for the same PWM controller microcircuit.

It is not even possible to find a datasheet for a specific microcircuit. Among other things, the repair is complicated by the abundance of SMD components, the marking of which is either difficult to read or it is impossible to purchase a replacement for the element.

It is worth noting that the overwhelming majority of laptop power adapters are made of very high quality. This can be seen at least by the presence of coil parts and chokes that are installed in the network filter circuit. It suppresses electromagnetic interference. In some low-quality power supplies from stationary PCs, such elements may be absent altogether.