A little about the application and design of the UPS

An article has already been published on the site, which tells about the UPS device. This topic can be somewhat supplemented with a short story about the repair. The abbreviation UPS is often referred to. So that there are no discrepancies, let us agree that in this article it is a Switching Power Supply.

Almost all switching power supplies used in electronic equipment are built according to two functional circuits.

Fig. 1. Functional diagrams of switching power supplies

As a rule, quite powerful power supplies, such as computer ones, are made according to the half-bridge circuit. Power supply units for powerful stage UMZCH and welding machines are also manufactured according to the push-pull scheme.

Anyone who has ever repaired amplifiers with a power of 400 watts or more knows very well what their weight is. Naturally, we are talking about UMZCH with a traditional transformer power supply. UPSs of TVs, monitors, DVD-players are most often made according to a scheme with a single-ended output stage.

Although in reality there are other types of output stages, which are shown in Figure 2.

Fig. 2. Output stages of switching power supplies

Only the power switches and the primary winding of the power transformer are shown here.

If you look closely at Figure 1, it is easy to see that the entire circuit can be divided into two parts - primary and secondary. The primary part contains a mains filter, a mains voltage rectifier, power switches and a power transformer. This part is galvanically connected to the AC mains.

In addition to the power transformer, decoupling transformers are also used in pulse power supplies, through which the control pulses of the PWM controller are fed to the gates (bases) of the power transistors. In this way, galvanic isolation from the secondary circuit is ensured. In more modern circuits, this decoupling is carried out using optocouplers.

The secondary circuits are galvanically isolated from the network using a power transformer: the voltage from the secondary windings is fed to the rectifier, and then to the load. The voltage stabilization and protection circuits are also powered from the secondary circuits.

Very simple switching power supplies

They are performed on the basis of an oscillator when there is no PWM master controller. An example of such a UPS is the Taschibra electronic transformer circuit.

Fig. 3. Electronic transformer Taschibra

Similar electronic transformers are produced by other companies. Their main purpose is. A distinctive feature of such a scheme is its simplicity and few details. The disadvantage is that this circuit simply does not start without load, the output voltage is unstable and has a high ripple level. But the bulbs still shine! In this case, the secondary circuit is completely decoupled from the supply network.

It is quite obvious that the repair of such a power supply is reduced to replacing transistors, resistors R4, R5, sometimes VDS1 and resistor R1, which acts as a fuse. There is simply nothing else in this scheme to burn out. With a low price of electronic transformers, a new one is often simply bought, and repairs are done, as they say, "out of love for art."

Safety first

As soon as there is such a very unpleasant neighborhood of primary and secondary circuits, which during the repair process it is imperative, even if accidentally, will have to be touched with your hands, then some safety rules should be recalled.

You can touch the switched on source only with one hand, in no case with both at once. Everyone who works with electrical installations knows this. But it is better not to touch at all, or, only after disconnecting from the network by pulling the plug out of the socket. Also, do not solder something on the switched on source or just twist it with a screwdriver.

In order to ensure electrical safety on the boards of power supplies, the "dangerous" primary side of the board is surrounded by a wide enough strip or shaded with thin stripes of paint, usually white. This is a warning that it is dangerous to touch this part of the board with your hands.

Even a switched off switching power supply can only be touched with your hands after a while, at least 2 ... 3 minutes after switching off: the charge on high-voltage capacitors remains for a long time, although in any normal power supply, discharge resistors are installed in parallel to the capacitors. Remember how the school offered each other a charged capacitor! Killing, of course, will not kill, but the blow is quite sensitive.

But the worst thing is not even that: well, just think, a little pinched. If you ring the electrolytic capacitor with a multimeter immediately after switching off, then it is quite possible to go to the store for a new one.

When such a measurement is expected, the capacitor must be discharged, at least with tweezers. But it is better to do this using a resistor with a resistance of several tens of KOhms. Otherwise, the discharge is accompanied by a bunch of sparks and a loud enough click, and such a short circuit is not very useful for a capacitor either.

And yet, during repairs, you have to touch the switched on switching power supply, at least to carry out some measurements. In this case, an isolation transformer, often called a safety transformer, will help to protect your loved one as much as possible from electric shock. You can read how to make it in the article.

In a nutshell, this is a transformer with two windings for 220V, with a capacity of 100 ... 200W (depending on the power of the UPS being repaired), the electrical circuit is shown in Figure 4.

Fig. 4. Safety transformer

The left winding according to the scheme is connected to the network, a faulty switching power supply is connected to the right winding through a light bulb. The most important thing with this inclusion is that with ONE hand you can touch any end of the secondary winding fearlessly, as well as all the elements of the primary circuit of the power supply.

About the role of the light bulb and its power

Most often, the repair of a switching power supply is carried out without an isolation transformer, but as an additional safety measure, the unit is turned on through a 60 ... 150W light bulb. By the behavior of the light bulb, you can, in general, judge the state of the power supply. Of course, such an inclusion will not provide a galvanic isolation from the network, it is not recommended to touch it with your hands, but it may well protect against smoke and explosions.

If, when switched on to the network, the lamp lights up at full incandescence, then you should look for a malfunction in the primary circuit. As a rule, this is a punctured power transistor or rectifier bridge. During normal operation of the power supply, the light first flashes brightly enough (), and then the filament continues to glow faintly.

There are several opinions about this light bulb. Someone says that it does not help to get rid of unforeseen situations, and someone believes that the risk of burning a newly sealed transistor is much reduced. We will adhere to this point of view, and use a light bulb for repairs.

About collapsible and non-collapsible cases

Most often, switching power supplies are made in housings. Suffice it to recall computer power supplies, various adapters plugged into an outlet, chargers for laptops, mobile phones, etc.

In the case of computer power supplies, everything is quite simple. Several screws are unscrewed from the metal case, the metal cover is removed and, please, the whole board with the details is already in your hands.

If the case is plastic, then you should look on the back side, where the power plug is located, for small screws. Then everything is simple and clear, he turned and removed the lid. In this case, we can say that it was just lucky.

But lately, everything has been going along the path of simplifying and reducing the cost of structures, and the halves of the plastic case are simply glued together, and quite firmly. One comrade told me how he drove a similar block to some workshop. When asked how to make it out, the masters said: "Are you not Russian?" Then they took a hammer and quickly split the body into two halves.

In fact, this is the only way to disassemble the plastic glued cases. But you need to pound carefully and not very fanatically: under the influence of blows to the body, the tracks leading to massive parts, for example, transformers or chokes, can break off.

A knife inserted into the seam also helps, and lightly tapping on it with the same hammer. However, after assembly, traces of this interference remain. But let there be minor marks on the case, but you don't have to buy a new unit.

How to find a schematic

If in the old days, circuit diagrams were attached to almost all domestic-made devices, then modern foreign electronics manufacturers do not want to share their secrets. All electronic equipment is completed only with a user manual, which shows which buttons to press. Schematic diagrams are not included with the user manual.

The device is expected to last forever or to be repaired at an authorized service center that has repair manuals called service manuals. Service centers do not have the right to share this documentation with everyone, but, praise the Internet, these service manuals can be found on many devices. Sometimes this can be obtained free of charge, that is, for nothing, and sometimes the necessary information can be obtained for a small amount.

But even if the desired circuit could not be found, you should not despair, especially when repairing power supplies. Almost everything becomes clear upon closer examination of the board. This powerful transistor is nothing more than an output switch, and this microcircuit is a PWM controller.

In some controllers, the power output transistor is "hidden" inside the microcircuit. If these parts are large enough, then they have full markings, according to which you can find the technical documentation (data sheet) of the microcircuit, transistor, diode or zener diode. It is these details that form the basis of switching power supplies.

It is somewhat more difficult to find datasheets for small-sized SMD components. The full marking on the small case does not fit; instead, a code designation of several (three, four) letters and numbers is placed on the case. Using this code, with the help of tables or special programs obtained again on the Internet, it is possible, though not always, to find the reference data of an unknown element.

Measuring instruments and tools

To repair switching power supplies, you will need the tool that every radio amateur should have. First of all, these are several screwdrivers, side cutters, tweezers, sometimes pliers and even the hammer mentioned above. This is for fitting and assembly work.

For soldering work, of course, you need a soldering iron, preferably several, of various powers and dimensions. An ordinary soldering iron with a power of 25 ... 40 W is quite suitable, but it is better if it is a modern soldering iron with a thermostat and temperature stabilization.

For soldering multi-pin parts, it is good to have at hand, if not super-expensive, then at least a simple inexpensive soldering hair dryer. This will allow you to solder multi-pin parts without much effort and destruction of printed circuit boards.

To measure voltages, resistances and, more rarely, currents, you will need a digital multimeter, even if not very expensive, or a good old arrow tester. The fact that it is too early to write off the pointer device, what additional features it provides that modern digital multimeters do not have, can be read in the article.

It can provide invaluable assistance in repairing switching power supplies. Here, too, it is quite possible to use an old, not even very broadband cathode-ray oscilloscope. If, of course, there is an opportunity to purchase a modern digital oscilloscope, then this is even better. But, as practice shows, when repairing switching power supplies, you can do without an oscilloscope.

Actually, during the repair, two outcomes are possible: either repair it, or make it even worse. Here it is appropriate to recall Horner's law: "Experience grows in direct proportion to the number of disabled equipment." And although this law contains a fair amount of humor, in the practice of repair, things are exactly like this. Especially at the beginning of the journey.

troubleshooting

Switching power supplies fail much more often than other components of electronic equipment. First of all, it is due to the fact that there is a high mains voltage, which becomes even higher after rectification and filtering. Therefore, the power switches and the entire inverter stage operate in a very difficult mode, both electrical and thermal. Most often, malfunctions lie precisely in the primary circuit.

Faults can be divided into two types. In the first case, the failure of the switching power supply is accompanied by smoke, explosions, destruction and charring of parts, sometimes tracks of the printed circuit board.

It would seem that the option is the simplest, you just need to change the burnt parts, restore the tracks, and everything will work. But when you try to determine the type of microcircuit or transistor, it turns out that the marking of the part has disappeared along with the case. What happened here, without a diagram, which is often not at hand, is impossible to find out. Sometimes the repair ends at this stage.

The second type of malfunction is quiet, as Lelik said, without noise and dust. The output voltages simply disappeared without a trace. If this switching power supply is a simple AC adapter like a charger for a cell or laptop, then the first thing to do is to check that the output cord is working properly.

Most often, a break occurs either near the output connector or at the exit from the case. If the unit is connected to the network using a cord with a plug, then first of all, you should make sure that it is working properly.

After checking these simplest circuits, you can already climb into the jungle. As this jungle, let's take the power supply circuit of the 19-inch LG_flatron_L1919s monitor. Actually, the malfunction was quite simple: it turned on yesterday, but today it does not turn on.

Despite the seeming seriousness of the device - after all, a monitor, the power supply circuit is quite simple and intuitive.

After opening the monitor, several swollen electrolytic capacitors (C202, C206, C207) were found at the output of the power supply. In this case, it is better to change all the capacitors at once, only six of them. The cost of these parts is cheap, so you shouldn't wait for them to swell too. After such a replacement, the monitor started working. By the way, such a malfunction is quite common with LG monitors.

The swollen capacitors triggered the protection circuit, the operation of which will be discussed a little later. If, after replacing the capacitors, the power supply does not work, you will have to look for other reasons. To do this, consider the diagram in more detail.

Fig 5. Power supply unit of the LG_flatron_L1919s monitor (click on the picture to enlarge)

Line filter and rectifier

The mains voltage through the input connector SC101, fuse F101, filter LF101 goes to the rectifier bridge BD101. The rectified voltage is fed through the thermistor TH101 to the smoothing capacitor C101. This capacitor produces a constant voltage of 310V, which is supplied to the inverter.

If this voltage is absent or much less than the specified value, then you should check the mains fuse F101, filter LF101, rectifier bridge BD101, capacitor C101, and thermistor TH101. All these parts are easy to check with a multimeter. If there is a suspicion of a capacitor C101, then it is better to change it to a known good one.

By the way, the mains fuse doesn't just blow out. In most cases, replacing it does not lead to the restoration of normal operation of the switching power supply. Therefore, you should look for other reasons leading to a blown fuse.

The fuse should be set at the same current as indicated in the diagram, and in no case should the fuse be overpowered. This can lead to even more serious malfunctions.

Inverter

The inverter is made according to a single-ended circuit. A PWM controller microcircuit U101 is used as a master oscillator, to the output of which a power transistor Q101 is connected. The primary winding of the transformer T101 is connected to the drain of this transistor through the choke FB101 (pins 3-5).

An additional winding 1-2 with a rectifier R111, D102, C103 is used to power the PWM controller U101 in the steady-state mode of the power supply. The PWM controller starts up when turned on by a resistor R108.

Output voltages

The power supply generates two voltages: 12V / 2A to power the inverter of the backlight lamps and 5V / 2A to power the logic part of the monitor.

From the winding 10-7 of the transformer T101 through the diode assembly D202 and the filter C204, L202, C205, a voltage of 5V / 2A is obtained.

A winding 8-6 is connected in series with the winding 10-7, from which a constant voltage of 12V / 2A is obtained using a diode assembly D201 and a filter C203, L201, C202, C206, C207.

Overload protection

Resistor R109 is connected to the source of transistor Q101. This is a current sensor, which is connected through a resistor R104 to pin 2 of the U101 microcircuit.

With an overload at the output, the current through the transistor Q101 increases, which leads to a voltage drop across the resistor R109, which is fed through the resistor R104 to the 2CS / FB pin of the U101 microcircuit and the controller stops generating control pulses (pin 6OUT). Therefore, the voltage at the output of the power supply disappears.

It was this protection that worked with swollen electrolytic capacitors, which were mentioned above.

Protection actuation level 0.9V. This level is set by the reference voltage source inside the microcircuit. In parallel with resistor R109, a zener diode ZD101 with a stabilization voltage of 3.3V is connected, which protects the 2CS / FB input from overvoltage.

A voltage of 310V is supplied to the 2CS / FB terminal through the divider R117, R118, R107 from the capacitor C101, which ensures the operation of the protection against the overvoltage of the network. The permissible range of the mains voltage, at which the monitor normally operates, is in the range of 90 ... 240V.

Output voltage stabilization

Made on an adjustable Zener diode U201 type A431. The output voltage 12V / 2A through the divider R204, R206 (both resistors with a tolerance of 1%) is fed to the control input R of the zener diode U201. As soon as the output voltage becomes equal to 12V, the zener diode opens and the LED of the PC201 optocoupler lights up.

As a result, the optocoupler transistor opens (pins 4, 3) and the controller supply voltage through the resistor R102 is supplied to the 2CS / FB pin. The pulses at the 6OUT pin disappear, and the voltage at the 12V / 2A output begins to drop.

The voltage at the control input R of the zener diode U201 drops below the reference voltage (2.5V), the zener diode turns off and turns off the PC201 optocoupler. At the 6OUT output, pulses appear, the 12V / 2A voltage begins to increase and the stabilization cycle repeats again. In a similar way, the stabilization circuit is built in many switching power supplies, for example, in computer ones.

Thus, it turns out that three signals are connected to the input of the 2CS / FB controller using a wired OR: overload protection, network overvoltage protection and the output of the output voltage stabilizer circuit.

Here it is just pertinent to recall how you can check the operation of this stabilization loop. For this, it is enough with OFF !!! from the mains power supply supply voltage from the regulated power supply to the 12V / 2A output.

It is better to hook on the output of the PC201 optocoupler with an arrow tester in the resistance measurement mode. As long as the voltage at the output of the regulated source is below 12V, the resistance at the output of the optocoupler will be large.

Now we will increase the voltage. As soon as the voltage becomes more than 12V, the arrow of the device will drop sharply in the direction of decreasing resistance. This suggests that the Zener diode U201 and the PC201 optocoupler are working properly. Therefore, the stabilization of the output voltages should work normally.

In exactly the same way, you can check the operation of the stabilization loop with computer switching power supplies. The main thing is to figure out what voltage the zener diode is connected to.

If all these checks are successful, and the power supply does not start, then you should check the Q101 transistor by removing it from the board. With a working transistor, most likely the U101 microcircuit or its strapping is to blame. First of all, this is an electrolytic capacitor C105, which is best checked by replacing it with a known good one.

If the computer's power supply does not work, the masters recommend checking its fan, and then taking on the troubleshooting of its other parts.

350 RUB RUB

The power supply unit is the main element of the electrics, it is through it that the power supply of all the main parts of the system unit is carried out. Its refusal will make it impossible to turn on and the correct operation of the device.

The cost of the service is 350 R.

A task worth entrusting to professionals! We will fulfill it with a guarantee and in the shortest possible time!

But how to check if the computer's power supply is working, how to find out the reason why it stopped working and what to do in case of any malfunctions? We will talk about this today.

How to check if a computer's power supply is working

As a rule, only a professional can determine the fact of a failure and find out why the computer's power supply does not work. For this, an autonomous load is supplied to the device. To perform this procedure, you need special resistors that must be connected to the terminals.

However, before that, you also need to select the necessary equipment, because if the resistors are not matched to the nominal power supply parameters, it will not work to establish whether the computer's power supply is really faulty.

So, after the main preparatory procedures are completed, the diagnosis itself begins.

It is done in two main ways:

• The influence of the motherboard. Two contacts are closed for testing. In this case, if the connector is designed for 20 sockets, you need to select wires 14 and 15, and if the connector uses 24 sockets, you will need wires 16 and 17. In both cases, these are "start" and "ground". If this does not activate the device cooler, then the computer's power supply is not working. If the fan starts rotating, the cause of the failure must be looked for elsewhere.
• Correspondence of the voltage at the power supply connectors to the required values. You should immediately pay attention to the fact that the manufacturer allows certain deviations from the norm. If a 12 Volt device is used, the error will be plus or minus 5%. If the power supply voltage has other values, fluctuations can reach up to 10%.

If the above conditions are not met, then the computer's power supply is defective. What to do in such a situation? More on this later.

Power supply repair

If your computer's power supply fails, it's best not to try to fix the problem yourself. This requires subtle knowledge of electronics and power supply devices, as well as skills in owning a soldering iron.

If you need computer help, call us and the experts of the "Expert" company will be happy to help you eliminate even the most serious malfunctions.

Eliminating such faults requires a step-by-step approach.

Power supply - the device is quite complex and there can be many reasons for breakdowns. Diagnostics and repair of the power supply unit should be carried out according to the following algorithm:

1. Dismantling the device, removing the cover and completely cleaning it from dust and dirt. It is they who lead to computer breakdowns in the overwhelming majority of cases; problems with the power supply are no exception. If the dust is in a thick layer, it becomes difficult to cool the elements, which leads to their overheating.
2. Visual inspection of the power supply board. For an experienced specialist, this procedure can tell a lot. Particular attention should be paid to capacitors. In the event of a short circuit in the PSU, they swell and flow. If the radio component is enlarged, and electrolyte is spilled around it, it must be replaced. Even if there are no external manifestations of problems on the capacitor, it will never be superfluous to measure it with a multitester.
3. Measurement of transitions of low-voltage diodes. It is possible that due to any power surges, they are out of order. This issue is also resolved by replacing the specified item.
4. Ring cracking and broken contacts can also be detected "by eye". The problem is relatively rare, but unfortunately it cannot be ruled out either. Soldering the contacts on the board will be the solution to this problem. However, it must be done very carefully so as not to aggravate the situation.
5. Blown fuse. If you encounter similar problems, you can consider yourself in luck. Replacing this PC element is not too difficult. Moreover, in principle, the element can even be repaired. The fuse must be removed from the bushing, a new one must be installed and fixed in place by soldering.

We will help you to repair the power supply

This list of faults is far from complete; a variety of power supply elements can fail. Moreover, sometimes there are situations in which

Self-repairing a computer power supply is a rather complicated matter. Having taken up this, you should clearly understand which of the components needs repair. Also, it should be understood that if the device is under warranty, then after any intervention, the warranty card will immediately expire.

If the user has little skills in working with an electrical appliance and is sure that he will not make mistakes, then you can safely take on such work. Remember to be careful when working with an electrical appliance.

Computer power supply circuit

To create a galvanic isolation, a large amount of winding is required. Based on this, a computer requires a very large power and it is natural that such a transformer for a PC should be large and heavy.

But due to the frequency of the current that is required to create the magnetic field, much fewer turns are required on the transformer. Thanks to this, when using the converter, small and light power supplies are created.

Power Supply- at first glance, a rather complicated device, but if a not particularly serious breakdown occurs, then it is quite possible to repair it yourself.

Below is a typical power supply circuit. As you can see, there is nothing complicated, the main thing is to do everything one by one so that there is no confusion:

Necessary repair tools

In order to start self-repairing a power supply unit, you should have the necessary tools at hand.

First, you need to arm yourself with devices for computer diagnostics:

• working power supply unit;
• post card;
• memory bar in working order;
• compatible type of video card;
• CPU;
• multimeter;

For the very same repair, you will need more:

• and everything for soldering;
• screwdrivers;
• the computer is in working order;
• oscilloscope;
• tweezers;
• insulating tape;
• pliers;

Naturally, this is not so much for a perfect repair, but this is enough for home repairs.

Step-by-step instruction

So, armed with all the necessary tools, you can start repairing:

1. First of all, you need to disconnect the system unit from the network and let it cool down a little.
2. All 4 screws are unscrewed one by one, that secure the back of the computer.
3. The same operation is carried out for the lateral surfaces. This work is done carefully so as not to touch the wires of the block. If there are screws that are hidden under the stickers, they also need to be unscrewed.
4. After the case has been removed completely, The PSU will need to be blown out (you can use a vacuum cleaner). You don't need to wipe anything with a damp cloth.
5. The next step there will be careful consideration and finding the cause of the problem.

In some cases, the power supply unit fails due to the microcircuit. Therefore, you should carefully examine its details. Particular attention should be paid to the fuse and the capacitor.

Often, the cause of a breakdown of a power supply is swollen capacitors, which break down due to poor performance of the cooler. This whole situation is easily diagnosed at home. It is enough just to carefully examine the top of the capacitor.

swollen capacitors

A convex lid is an indicator of fracture. In ideal condition, the condenser is a flat cylinder with flat walls.

To eliminate this breakdown you will need:

1. Extract broken capacitor.
2. In its place a new serviceable part similar to the broken one is installed.
3. Cooler is removed, its blades are cleaned from dust and other particles.

To avoid exposing your computer to overheating, it should be purged regularly.

In order to check the fuse in another way, it is not necessary to unsolder it, but rather connect the copper core to the contacts. If the power supply unit starts to work, then it is enough just to solder the fuse, perhaps it just moved away from the contacts.

To check the fuse is working, just turn on the power supply. If it burns out a second time, then you need to look for the cause of the breakdown in other details.

The next breakdown option may depend on the varistor. It is used to pass current and equalize it. Signs of its malfunction are traces of carbon deposits or black spots. If such were found, the part must be replaced with a new one.

varistor

Note! The varistor is the part of the computer that is checked when it is turned on, so you need to be careful and attentive. Each individual part is checked according to a similar principle: resistors, capacitor.

It should be noted that checking and replacing diodes is not an easy task. To check them, each diode should be evaporated separately or the entire part at once. They should be replaced with similar parts with the stated voltage.

If, after replacing the transistors, they burn out again, then you should look for the cause in the transformer. By the way, this part is hard enough to find and buy. In such situations, experienced craftsmen recommend buying a new PSU. Fortunately, such a breakdown is rare.

Another reason for the breakdown of the power supply unit may be associated with annular cracks that break the contacts. This can also be detected visually by carefully examining the printed strip. You can eliminate such a defect with a soldering iron by performing a thorough soldering, but you must be good at soldering. With the slightest mistake, you can break the integrity of the contacts and then you will have to change the entire part as a whole.

ring cracks

If a more complex breakdown is found, then excellent technical training is required. Also, you will have to use complex measuring instruments. But it should be noted that the purchase of such devices will cost more than the entire repair.

You should be aware that the elements that require replacement are sometimes in short supply and not only are they difficult to obtain, they are also expensive. If a complex breakdown occurs and the repair costs exceed the price compared to purchasing a new power supply. In this case, it will be more profitable and more reliable to purchase a new device.

Functional check

After the reasons that brought the power supply out of the operating mode have been eliminated, it must be checked.

The most elementary operation Is to turn on the computer to the network. But, by the way, this can be done without connecting a PC. It is enough to connect any load to the power supply unit, for example a CD-ROM, after which you need to short-circuit the green and black wires in the power supply connector and turn it on.

If everything is in order, then the fan and the drive LED on the working power supply will immediately turn on. And naturally, the reverse reaction of the power supply unit (if nothing started working), then the cause has not been eliminated.

After the serviceability of the device is confirmed, you can start assembling the system unit.

Before undertaking an independent repair of the power supply, you need to be confident enough in your knowledge of electrical appliances:

1. To start you can read the literature, which can be easily found on the Internet, where the causes and symptoms of a power supply breakdown are described in detail.
2. We need to study the scheme.
3. Before than to start disassembling the system unit, make sure that it is disconnected from the network. It will be better if it is completely chilled.
4. Dust and any dirt must be blown out with a vacuum cleaner or hair dryer. It is not recommended to use a damp cloth.
5. Study all the details should be carried out in turn. It is advisable to check the power supply every time.
6. If you don't have the skills to work with a soldering iron, but soldering is indispensable, it is better to contact a specialist, it will be cheaper.
7. When, if spare parts and repairs are more expensive than a new power supply unit, then it is better to think about purchasing a new part.
8. Before, how to start repairing the power supply, you need to make sure that the power cable and switch are in good working order.

Signs of a Broken Power Supply

A power supply malfunction will not occur from scratch. If there are signs that indicate its malfunction, then before starting the repair, you must first eliminate the causes that led to its failure.

Causes:

1. Poor quality supply voltage (voltage drops).
2. Not very high quality components Components.
3. Defects, which were approved at the factory.
4. Bad installation.
5. Location of parts on the plate of the power supply unit is located in such a way that it leads to contamination and overheating.

Signs:

1. The computer may not turn on, and if you open the system unit, you can find that the motherboard is not working.
2. PSU can and work, but the operating system does not start.
3. When turning on the PC everything seems to start working, but after a while everything turns off. The protection of the power supply may be triggered.
4. The appearance of an unpleasant odor.

The failure of the power supply unit cannot be missed, since problems begin with turning on the system unit (it does not turn on at all), or after a few minutes of operation it turns off.

If at least one of the problems is noticed, you should think about eliminating the malfunction, otherwise, the computer may fail altogether, and then you cannot do without the intervention of an experienced specialist.

Major problems:

1. The most common moment that can affect the operation of the power supply is the swelling of the capacitor. A similar problem can be determined only after opening the power supply unit and completely inspecting the capacitor.
2. If at least 1 diode fails, then the entire diode bridge also fails.
3. Burning resistors, which are located near capacitors, transistors. If such a problem occurs, then it will be necessary to look for the problem in the entire electrical circuit.
4. Problems with the PWM controller. It is quite difficult to check it, for this you need to use an oscilloscope.
5. Power transistors also often fail. A multimeter is used to check them.

Note! Power capacitors tend to hold a charge for some time; therefore, it is not recommended to touch them with bare hands after the power is turned off. Also, it should be remembered that when the power supply is connected to the network, you do not need to touch the stove or radiator.

Repair cost

If you perform an independent repair of the power supply and do not have the necessary tools at hand, then first of all you will have to spend money on their purchase. This amount can reach from 1000 rubles to 5000 rubles.

As for the power supply unit itself, everything depends on the parts that have become unusable. On average, repairs can cost up to 1,500 thousand rubles.

For your information: a used power supply unit in good condition can cost 2,000 - 2,500 rubles. This applies to models for older computers. Modern PCs are equipped with more expensive PSUs.

In a service center, a similar procedure can cost about the same amount. But at the same time, it should be remembered that a specialist always gives a guarantee for his work.

Sent yuri11112222- Power supply circuitry: ATX-350WP4
Power supply circuitry: ATX-350WP4

The article offers information on circuit solutions, recommendations for repair, replacement of analog parts for the ATX-350WP4 power supply. Unfortunately, the author could not establish the exact manufacturer, apparently, this assembly of the block is close enough to the original, presumably Delux ATX-350WP4 (Shenzhen Delux Industry Co., Ltd), the appearance of the block is shown in the photo.

General information. The power supply is implemented in the ATX12V 2.0 format, adapted for the domestic consumer, therefore it does not have a power switch and a switch for the type of variable network. Output connectors include:
connector for connecting to the system board - main 24-pin power connector;
4-pin +12 V connector (P4 connector);
removable media power connectors;
powering a Serial ATA hard drive. It is assumed that the main power connector is
can be easily converted to 20-pin by dropping the 4-pin group, making it compatible with older motherboards. The 24-pin connector allows the maximum power of the connector using standard 373.2W terminals.
Operational information for the ATX-350WP4 power supply is given in Table.

Structural scheme. The set of elements of the structural diagram of the ATX-350WP4 power supply is typical for pulse-type power supplies. These include a two-tier line suppression filter, a low-frequency high-voltage rectifier with a filter, main and auxiliary pulse converters, high-frequency rectifiers, an output voltage monitor, protection and cooling elements. A feature of this type of power supply is the presence of a supply voltage at the input connector of the power supply, while a number of elements of the unit are energized, there is voltage at some of its outputs, in particular, at the + 5V_SB outputs. The block diagram of the source is shown in Fig. 1.

Power supply operation. The rectified mains voltage of about 300 V is the supply for the main and auxiliary converters. In addition, a supply voltage is supplied from the output rectifier of the auxiliary converter to the control microcircuit of the main converter. In the off state (the PS_On signal has a high level) of the power supply, the main converter is in "sleep" mode, in this case the voltage at its outputs is not recorded by the measuring devices. At the same time, the auxiliary converter produces the main converter supply voltage and the + 5B_SB output voltage. This power supply acts as a standby power supply.

The main converter is switched on according to the principle of remote switching, according to which the Ps_On signal becomes equal to zero potential (low voltage level) when the computer is turned on. According to this signal, the output voltage monitor issues a permission signal for the formation of control pulses of the PWM controller of the main converter of the maximum duration. The main transducer wakes up from sleep mode. From high-frequency rectifiers through appropriate smoothing filters, voltages of ± 12 V, ± 5 V and +3.3 V are supplied to the power supply output.

With a delay of 0.1 ... 0.5 s relative to the appearance of the PS_On signal, but sufficient for the end of transient processes in the main converter and the formation of supply voltages of +3.3 V. +5 V, +12 V at the output of the power supply, by a monitor output voltages, the RG signal is generated. (food is normal). P.G. signal is informational, indicating the normal operation of the power supply. It is issued to the motherboard for initial installation and startup of the processor. Thus, the Ps_On signal controls the power-on of the power supply, and the P.G. responsible for starting the motherboard, both signals are included in the 24-pin connector.
The main converter uses a pulse mode, the converter is controlled by a PWM controller. The duration of the open state of the converter keys determines the voltage value of the output sources, which can be stabilized within the permissible load.

The power supply status is monitored by the output voltage monitor. In case of overload or underload, the monitor generates signals that prohibit the operation of the PWM controller of the main converter, putting it into sleep mode.
A similar situation arises in the conditions of emergency operation of the power supply associated with short circuits in the load, which are monitored by a special control circuit. To facilitate thermal conditions in the power supply, forced cooling is used, based on the principle of creating negative pressure (release of warm air).

The schematic diagram of the power supply is shown in Fig. 2.

The mains filter and low-frequency rectifier use elements of protection against mains interference, after passing through the mains voltage is rectified by a bridge-type rectifier circuit. Output voltage protection against noise in the AC mains is carried out by means of a pair of suppressor filter links. The first link is made on a separate board, the elements of which are CX1, FL1, the second link is made up of the elements of the main board of the power supply CX, CY1, CY2, FL1. Elements T, THR1 protect the power supply from short-circuit currents in the load and voltage surges in the input network.
The bridge rectifier is made on diodes B1-B4. Capacitors C1, C2 form a low-frequency network filter. Resistors R2, R3 are elements of the discharge circuit of capacitors C1, C2 when the power is turned off. Varistors V3, V4 limit the rectified voltage in case of line voltage surges above the accepted limits.
The auxiliary converter is connected directly to the output of the mains rectifier and schematically represents a self-oscillating blocking generator. The active elements of the block-king generator are transistor Q1 n-channel field-effect transistor (MOSFET) and transformer T1. The initial gate current of transistor Q1 is generated by resistor R11R12. At the moment of power supply, the blocking process begins to develop, and current begins to flow through the working winding of the transformer T1. The magnetic flux created by this current induces an EMF in the positive feedback winding. In this case, capacitor C7 is charged through the diode D5 connected to this winding, and the transformer is magnetized. The magnetizing current and the charging current of the capacitor C7 lead to a decrease in the gate current of Q1 and its subsequent blocking. Damping of the discharge in the drain circuit is carried out by the elements R19, C8, D6, the reliable blocking of the transistor Q1 is carried out by the bipolar transistor Q4.

The main converter of the power supply is made according to a push-pull half-bridge circuit (Fig. 3). The power part of the converter is transistorized - Q2, Q3, reversely connected diodes D1, D2 provide protection of the transistors of the converter from "through currents". The second half of the bridge is formed by capacitors C1, C2, which create a rectified voltage divider. The diagonal of this bridge includes the primary windings of transformers T2 and TZ, the first of them is rectifier, and the second functions in the control circuit and protection against "excessive" currents in the converter. To exclude the possibility of asymmetric biasing of the TZ transformer, which can occur during transient processes in the converter, an isolation capacitor SZ is used. The operating mode of the transistors is set by the elements R5, R8, R7, R9.
Control pulses to the transistors of the converter are fed through the matching transformer T2. However, the start of the converter occurs in a self-oscillating mode, when the transistor 03 is open, the current flows through the circuit:
+ U (B1 ... B4) -> Q3 (k-e) -> T2 - T3 -> C3 -> C2 -> -U (BL..B4).

In the case of an open transistor Q2, the current flows through the circuit:
+ U (B1 ... B4) -> C1 -> C3 -> T3 -> T2 -> Q2 (to-e) -> -U (B1 ... B4).

Through the transition capacitors C5, C6 and limiting resistors R5, R7, control signals enter the base of the key transistors, the notch circuit R4C4 prevents the penetration of impulse noise into the alternating electrical network. Diode D3 and resistor R6 form the discharge circuit of the capacitor C5, and D4 and R10 form the discharge circuit Sb.
When current flows through the primary winding of the TZ, the process of energy accumulation by the transformer takes place, the transfer of this energy to the secondary circuits of the power source and the charge of the capacitors C1, C2. The steady-state mode of operation of the converter will begin after the total voltage across the capacitors C1, C2 reaches +310 V. At the same time, power will appear on the U3 microcircuit (pin 12) from a source made on the elements D9, R20, C15, C16.
The converter is controlled by a cascade made on transistors Q5, Q6 (Fig. 3). The load of the cascade is the symmetrical half-windings of the transformer T2, at the connection point of which the supply voltage +16 V is supplied through the elements D9, R23. The operating mode of transistors Q5 and Q6 is set by resistors R33, R32, respectively. The cascade is controlled by pulses of the PWM shaper microcircuit U3, coming from pins 8 and 11 to the base of the cascade transistors. Under the influence of control pulses, one of the transistors, for example Q5, opens, and the second, Q6, respectively, closes. Reliable locking of the transistor is carried out by the D15D16C17 chain. So, when current flows through the open transistor Q5 along the circuit:
+ 16V -> D9 -> R23 -> T2 -> Q5 (to-e) -> D15, D16 -> case.

A voltage drop of +1.6 V is formed in the emitter of this transistor. This value is enough to turn off the transistor Q6. The presence of the capacitor C17 helps to maintain the blocking potential during the "pause".
Diodes D13, D14 are designed to dissipate the magnetic energy accumulated in the half-windings of the transformer T2.
The PWM controller is based on an AZ7500BP microcircuit (BCD Semiconductor) operating in push-pull mode. The elements of the generator timing circuit are capacitor C28 and resistor R45. Resistor R47 and capacitor C29 form an error amplifier correction circuit 1 (fig. 4).

To implement the push-pull mode of the converter operation, the control input of the output stages (pin 13) is connected to a reference voltage source (pin 14). From pins 8 and 11 of the microcircuit, control pulses enter the base circuits of transistors Q5, Q6 of the control cascade. Voltage +16 V is supplied to the microcircuit power output (pin 12) from the auxiliary converter rectifier.

The "slow start" mode is implemented using an error amplifier 2, the non-inverting input of which (pin 16 U3) receives a supply voltage of +16 V through the divider R33R34R36R37C21, and the inverting input (pin 15) receives a voltage from the reference source (pin 14 ) from the integrating capacitor C20 and the resistor R39.
The sum of voltages of +12 V and +3.3 V is supplied to the non-inverting input of the error amplifier 1 (pin. 1 U3) through the adder R42R43R48. The voltage from the reference source of the microcircuit (pin. 14 U3). Resistor R47 and capacitor C29 are frequency correction elements of the amplifier.
Stabilization and protection chains. The duration of the output pulses of the PWM controller (pin 8, 11 U3) in the steady state is determined by the feedback signals and the sawtooth voltage of the master oscillator. The time interval during which the "saw" exceeds the feedback voltage determines the duration of the output pulse. Let's consider the process of their formation.

From the output of the error amplifier 1 (pin 3 of U3), information about the deviation of the output voltages from the nominal value in the form of a slowly varying voltage is sent to the PWM driver. Further, from the output of the error amplifier 1, the voltage is supplied to one of the inputs of the pulse-width modulator (PWM). Its second input receives a sawtooth voltage with an amplitude of +3.2 V. Obviously, when the output voltage deviates from the nominal values, for example, downward, the feedback voltage will decrease at the same value of the sawtooth voltage supplied to the pin. 1, which leads to an increase in the duration of the output pulse cycles. In this case, more electromagnetic energy is accumulated in the transformer T1, which is given to the load, as a result of which the output voltage rises to the nominal value.
In the emergency mode of operation, the voltage drop across the resistor R46 increases. In this case, the voltage at pin 4 of the U3 microcircuit increases, and this, in turn, leads to the operation of the "pause" comparator and a subsequent decrease in the duration of the output pulses and, accordingly, to the limitation of the current flow through the transistors of the converter, thereby preventing the output of Q1, Q2 from building.

The source also has short-circuit protection circuits in the output voltage channels. The short-circuit sensor on the -12 V and -5 V channels is formed by the elements R73, D29, the midpoint of which is connected to the base of the transistor Q10 through the resistor R72. Here, through the resistor R71, the voltage from the +5 V source is supplied. Therefore, the presence of a short circuit in the -12 V (or -5 V) channels will lead to the unlocking of the Q10 transistor and an overload on terminal 6 of the voltage monitor U4, and this, in turn, will stop the operation of the converter at pin 4 of the converter U3.
Management, control and protection of the power supply. Almost all computers, in addition to high-quality performance of its functions, require easy and quick on / off. The task of turning on / off the power source is solved by implementing the principle of remote on / off in modern computers. When you press the "I / O" button located on the front panel of the computer case, the processor board generates the PS_On signal. To turn on the power supply, the PS_On signal must have a low potential, i.e. zero, when turned off - high potential.

In the power supply, the tasks of control, monitoring and protection are implemented on the U4 microcircuit of the monitor of the output voltages of the LP7510 power supply. When a zero potential (PS_On signal) arrives at pin 4 of the microcircuit, a zero potential is also formed at pin 3 with a delay of 2.3 ms. This signal is the trigger for the power supply. If the PS_On signal is high or its input circuit is broken, then pin 3 of the microcircuit is also set to a high level.
In addition, the U4 microcircuit monitors the main output voltages of the power supply. So, the output voltages of 3.3 V and 5 V power supplies should not go beyond the established limits of 2.2 V< 3,3В < 3,9 В и 3,5 В < 5 В < 6,1 В. В случае их выхода за эти пределы более чем на 146 мкс на выходе 3 микросхемы U4 устанавливается высокий уровень напряжения, и источник питания выключается по входу 4 микросхемы U3. Для источника питания +12 В, контролируемого по выводу 7, существует только контроль над его превышением. Напряжение питания этого источника не должно превышать больше чем 14,4 В. В перечисленных аварийных режимах основной преобразователь переходит в спящий режим путем установления на выводе 3 микросхемы U4 напряжения высокого уровня. Таким способом осуществляется контроль и защита блока питания от понижения и повышения напряжения на выходах его основных источников (рис.5).

In all cases of a high voltage level at pin 3, the voltage at pin 8 is normal, PG is low (zero). In the case when all supply voltages are normal, a low level of the PSOn signal is set at pin 4, and a voltage not exceeding 1.15 V is present at pin 1, a high level signal appears at pin 8 with a delay of 300 ms.
The thermoregulation circuit is designed to maintain the temperature regime inside the power supply case. The circuit consists of a fan and a THR2 thermistor, which are connected to the + 12V channel. Maintaining a constant temperature inside the case is achieved by adjusting the fan speed.
Pulse voltage rectifiers use a typical full-wave midpoint rectifier circuit to provide the required ripple ratio.
The rectifier of the power supply +5 V_SB is made on the diode D12. The two-tier output voltage filter consists of a capacitor C15, an inductor L3 and a capacitor C19. Resistor R36 is a load resistor. Stabilization of this voltage is carried out by microcircuits U1, U2.

The +5 V power supply is made on the D32 diode assembly. The two-link filter of the output voltage is formed by the winding L6.2 of a multi-winding choke, choke L10, capacitors C39, C40. Resistor R69 is a load resistor.
The +12 V power supply is made in the same way. Its rectifier is implemented on the D31 diode assembly. The two-link filter of the output voltage is formed by the winding L6.3 of a multi-winding choke, choke L9, capacitor C38. Power supply load - thermoregulation circuit.
Voltage rectifier +3.3 V - diode assembly D30. The circuit uses a parallel type regulator with a regulating transistor Q9 and a parametric regulator U5. The voltage is supplied to the control input U5 from the divider R63R58. Resistor R67 is the load of the divider.
To reduce the level of interference emitted by pulse rectifiers into the electrical network, resistive-capacitive filters on the elements R20, R21, СЮ, С11 are connected in parallel to the secondary windings of the transformer T1.
Power supplies of negative voltages -12 V, -5 V are formed in the same way. So for a 12 V source, the rectifier is made on diodes D24, D25, D26, smoothing filter L6.4L5C42, resistor R74 - load.
Voltage -5 V is generated by diodes D27, 28. The filters of these sources are -L6.1L4C41. Resistor R75 is a load resistor.

Typical malfunctions
Mains fuse T blown or no output voltages. In this case, it is necessary to check the health of the elements of the barrier filter and the mains rectifier (B1-B4, THR1, C1, C2, V3, V4, R2, R3), and also check the health of the transistors Q2, Q3. Most often, if the wrong AC network is selected, the varistors V3, V4 burn out.
The serviceability of the elements of the auxiliary converter, transistors Q1.Q4 is also checked.
If the malfunction is not detected and the failure and operation of the previously considered elements was not confirmed, then the presence of a voltage of 310 V on the series-connected capacitors C1, C2 is checked. In its absence, the serviceability of the network rectifier elements is checked.
Voltage + 5 \ / _ ZV is higher or lower than normal. Check the stability of the stabilization circuit U1, U2, the defective element is replaced. TL431, КА431 can be used as a replacement element for U2.
Output supply voltages are higher or lower than normal. We check the serviceability of the feedback circuit - the U3 microcircuit, the U3 microcircuit strapping elements: capacitors C21, C22, C16. If the above elements are in good condition, replace U3. The chips TL494, KA7500V, MV3759 can be used as U3 analogs.
P.G. signal missing. Check the presence of the Ps_On signal, the presence of supply voltages +12 V, +5 V, +3.3 V, +5 B_SB. If available, replace the U4 microcircuit. The TPS3510 can be used as an analogue of the LP7510.
There is no remote turn-on of the power supply. Check for the presence of the housing potential (zero) on the PS-ON contact, the serviceability of the U4 microcircuit and its strapping elements. If the trim elements are in good condition, replace U4.
No fan rotation. Make sure that the fan is working, check the elements of its switching circuit: the presence of +12 V, the serviceability of the THR2 thermistor.

D. Kucherov, Radioamator magazine, No. 3, 5 2011

ADDED 10/07/2012 04:08 AM

On my own I will add:
Today I had to make myself a power supply unit to replace the again burnt out (I think I won't be able to repair it soon) Chieftec 1KWt. I had a 500W Topower silent.

In principle, a good European power supply unit, with honest power. Problem - protection is triggered. Those. with normal duty, only a short start. Pulled the valve and truncated.
I did not find a short circuit on the main tires, I began to investigate - miracles do not happen. And finally I found what I was looking for - a -12v bus. A banal defect - a broken diode, did not even consider which one. Just replaced it with HER207.
I installed this PSU in my system - the flight is normal.

Instructions

Do not open the power supply to troubleshoot it. This is the lot of specialists. It is not necessary to disassemble the system unit to determine the malfunction of this critical component. Be attentive to the operation of your computer.

Recall if there are frequent restarts and freezes of the computer for no apparent reason (while the computer is performing simple tasks). Note for yourself the appearance of errors in the work of programs and the operating system as a whole. Errors in the functioning of the RAM during testing and during further work in the system. Interruptions in the operation of the hard disk or the failure of the latter indicate a loss of voltage at the output of the power supply.

Pay attention to the appearance of an unpleasant smell and excessive heating of the system unit. These are undoubted malfunctions of your computer's power supply.

If your computer shows no signs of life, you will have to disassemble it. Disconnect the power cable from the system unit. Take a screwdriver. Unscrew the screws that hold the wall of the system unit to your right. Remove the cover to access the motherboard.

From the socket on the motherboard, remove the main plug of the power supply connector, which has 20 or 24 pins. Find the third and fourth pins, green and black wires lead to them. Close these two contacts using a regular paper clip. Plug in the power cord. In a working power supply unit, the fan will start, and voltage will appear on its terminals.

Measure the voltage with a voltmeter. Between the contacts of the black and red wires, it will be 5 volts, black and yellow - 12 volts, black and orange - 3.3 volts (minus on black and plus on colored ones). If the values ​​you received differ from the above, your power supply is defective.

Many users are concerned about whether their computer is “powerful”. At the same time, the main difficulty is that in different tasks the computer demonstrates different performance, and, in general, there is no single numerical expression for "computer power". There are a huge number of testing programs that determine the ability of a computer to perform certain tasks, with varying degrees of specialization.

You will need

• Computer, basic computer skills, 3DMark test software, PassMark or similar

Instructions

Microsoft came closest to creating a unified rating scale. In the latest versions of their operating systems, there is such a feature as computer performance. To use this feature, activate the Computer tab in the Start menu. In the window that appears, select the "System Properties" menu item. Find the line "Score", which displays a certain. This is an assessment of the performance of a computer. By clicking on the "Windows Performance Index" hyperlink next to it, you can find out what constitutes the score. The disadvantage of this estimate is its very low accuracy and low information content.

The rest of the methods for determining the "power" of a computer are focused on certain types of applications. One of the most popular test suite, 3DMark, mainly identifies the computer. To find out the "gaming score" of your computer, install 3DMark and run a standard benchmark. You will receive a number in points, which will reflect the power of the computer in games. You can compare your result with others on the Internet.

The computing power of a computer is determined using other test programs, one of which is PassMark. After completing it, you will receive an estimate of the processor power, also in points. The developer's website contains a huge statistics of the tests performed, and on it you can compare your result with the ratings of other users.

note

On the Internet for a long time already, there has been an orderly overgrown with a beard instructions on how to determine the gender of your computer. To determine if your computer is a man or a woman, open Notepad and copy the following text there, without external quotes: "CreateObject (" SAPI.SpVoice "). Speak" I love you "".

Helpful advice

In order to find out what gender your computer is, you need to do a very simple operation: 1) Open notepad. 2) Copy this phrase into it - CreateObject ("SAPI.SpVoice"). Speak "I love you". In general, GetVoices - gives a voice preinstalled in the system. Using the search, you can sort through the voices and choose the one you like if the existing floor of the computer does not suit you.

Sources:

• PassMark
• how to find out the gender of the computer

The power of the power supply is a very important characteristic of the computer, which is designed to ensure its uninterrupted and full-fledged functioning. The higher it is, the better. But there is a minimum value that must match the specifications of the computer.

Instructions

The more powerful the "" computer, the more powerful you need it. As a rule, the manufacturer's power is on the unit itself on a special sticker. To find out the required power, there are various services. ASUS has a corresponding form on its website, after filling it out, the program will display the desired value based on the maximum possible computer components.

In the CPU section, specify the parameters of your processor manufacturer. In the Select Vendor field, select the kernel manufacturer, in the CPU Type select the processor family, and in the Select CPU field, specify the model itself.

In the VGA Card section, the values ​​for the computer's video card are indicated, where Vendor is the manufacturer of ATI or Nvidia, and in "Select VGA" is the model of the video card, which can be found in the control panel of the card driver (right-click on "My Computer" - "Properties" - " Device Manager "-" Video adapters ").

In Memory Module, specify the type of RAM used (DDR, DDRII, DDRIII).

In the Storage Devices menu, specify the number of read / write devices connected to the computer. In the USB section, specify the devices connected to USB. In paragraph 1394, mark the presence of an additional card for video capture, and in the PCI section select the available devices (Modem, Network (LAN), Audio, and other PCI card - the number of network devices and sound cards connected to the PCI slot in the motherboard, and SCSI card - the number of cards for connecting a SCSI bridge).

The program will automatically give the optimal value, which should not be lower than the one indicated on the power supply sticker. Otherwise, the unit should be replaced with a more powerful one in a computer repair service.

Sources:

• ASUS Optimum Power Testing Service

When buying computer equipment, it is very important to pay attention to such characteristics as the power of the power supply. It is she who ensures the constant operation of the equipment. In this case, it is desirable to take into account the fact that the power must be sufficiently high.

You will need

• - the Internet;
• - a computer.

Instructions

To determine the required capacity, there are various services on which you can find the necessary information. For example, visit the ASUS website ( http://ru.asus.com/) and fill in the required form there. After that, it will determine the required value of the power supply unit, being guided by the maximum power consumption of the computer components.

To view the required capacity, you can also visit the service page. Enter the Motheboard field, select Desktop (if using a home system) or Server (if testing a server). In the CPU field, you need to specify all the parameters of the manufacturer of the processor of your computer. In this case, the manufacturer of the core is indicated in the "Select Vendor" item, the processor family - in the CPU Type, specify its model in the "Select CPU" field.

Next, in the VGA Card field, you must mark the value for the computer's video card. In the "Select VGA" item, specify the model of the video card. To find out this information, right-click on "My Computer", then go along the following chain: "Properties" -> "Device Manager" -> "Video adapters". After that, in the Memory Module field, indicate the type of RAM used in your computer.