How to ring the power supply of a computer with a multimeter. Diagnostics of the computer power supply. Briefly about the power supply

How to check the power supply of a computer. The computer does not turn on.

So, the power cord from the outlet to the computer's power supply has been checked. Thus, the required voltage is suitable for the power supply. But when I press the power button, nothing happens and the computer does not turn on. It is most likely a power supply failure. You can independently check the power supply, its health, and at least try to determine for what reason the computer's power supply does not work.

Well, you have to free the computer from the side cover from the side of the vent. The second one is not required. If the fans do not spin when you press the power button, there are only a few options. The main reasons: the power supply or the power button is faulty. Yes, anything can happen, and it could just be a button malfunction or a wire break from the button to the connector on. Let's select the direction in which we will move.

What will we need?

• a short circuit in the form of a metal wire, a small piece of wire of a small cross section; I use a resistor type radio element with a nominal value of 1 kOhm, but for a one-time experience and scrapers will be enough; however, I advise you not to leave a PSU with a scraper for a long time: the smaller the cross section, the stronger our impromptu short circuit will warm up
• (if you are going to check not only the PSU performance, but also the voltage through the main load channels)

I propose to divide the entire verification procedure into the following stages:

Does the button itself work?

To separate the power supply failure from the button failure, we do not need to remove the power supply itself yet. First, unplug the computer's power cord from the outlet or turn off the power button on the back of the power supply.

With the lid open, trace the path of the power-on wires and the "LED" wires from the front of the computer to the motherboard. It is not difficult to find them, they have a mixed (red, blue, black and green wires) color designation and, ending with jackers, are connected to the “male” connectors of the motherboard. These connectors are usually found in the bottom quadrant of the board.

Our task is to highlight the connector that is responsible for turning on the computer from the button. The voltage on the motherboard is low and there is no need to be afraid of an electric discharge. The only advice is to try not to damage the motherboard while you are trying to check the power supply with the manipulations described below.

The desired connector is easy to determine. It is indicated by letters with the participation of the letters PW or POWER(from English - food). As in the photo below, it almost always has a similar color scheme of wires - green ( red or blue) plus white (rarely others). But given the fact that we do not know who built our computer, the best way to determine the ownership of any wires is the picture next to these connectors. As you can see in the photo, the right side of the figure is indicated by these letters. So this is the power button. It is connected by two wires and it will also help us check the power supply.

the connection diagram is drawn directly on the board, and the connectors themselves are no longer included in the photo, they are slightly to the right of the shooting area

The specified characters are required for the power button. Pull towards you and remove the jacker from the socket. Remember it. In the next step, the protruding pins will close together. The next step is to plug the power cord into an outlet or turn on the button on the power supply.

Now let's try to check the power supply for start

Using the flat tip of a small screwdriver, a scissors blade or a paper clip, briefly bridge the motherboard contacts that have been released from the power button jack as shown in the photo. Try a few times.

• If the power supply is good and working itself, the computer will turn on and continue to work. It will be possible to turn off the computer by simply turning it off from the button on the power supply, pulling out the plug from the socket, or re-closing the same contacts with a screwdriver, but holding it until it turns off.
• If the coolers of the power supply, processor cooling and cooling of the system unit (if any) turned on, but this did not happen from the button assembly, the power supply is in order and the malfunction lies in the power button.
• If the computer does not respond to manipulations, proceed to the next step.

Disconnect the main ATX connector from the power supply to the motherboard. This is the largest connector, you can’t confuse it with anything. This is a 24-pin (or 20 + 4) connector:

The camera flash ruined the view a bit...

Press the plastic lock on the side with your thumb (or forefinger), releasing the connector for dismantling, and pull the connector towards you with swaying longitudinal movements. Rest your free fingers, if necessary, on the motherboard. Do not break (although I have never broken).

Now let's try to check the power supply and run it directly

In the assembled circuit, the signal to turn on goes from the button through the motherboard to the green contact of the connector that you hold in your hands. We bypass the board and close this contact to any of the black wires. To check the power supply, contact closure black and green colors will be carried out for a short time. This means that you can use any means at hand: a paper clip, tweezers, etc. Do not be afraid of electric shock, the voltage in this part of the system is absolutely safe. Contacts that will be closed are located nearby: they have conditional numbering 15 and 16 (remember this: numbering will come in handy when looking for other contacts). The black wire is “earth” (empty), the green one, when the wire is plugged into the socket, carries voltage. You can short circuit directly when plugged into a power outlet; you will not suffer, the voltage is scanty and not dangerous for a person:

If the power supply continues to be silent, the coolers do not want to spin, the fault lies in the power supply. In the language of electrical engineering, this means that the voltage in this section of the power supply circuit is less than the prescribed 5 V. More on this in another article. You can call a specialist or continue the search yourself.

It's time to check the power supply with the device

If the power supply came to life, we proceed to measurements with the device. Turn off the power supply temporarily. Set the multimeter to measure constant voltage values. On the instrument carriage, this is a sector with symbols V- :

and immediately set the measurement limit to 20 volts:

I will remove the main consumers (disks, floppy drives, power to the video card) of the computer from the power and signal loops:

hard drive disabled

And behind it is a DVD drive:

We turn on the computer in the socket or the key on the PSU at the back. With the power supply turned on (the cooler is spinning in it), I check the voltage at the terminals of the 24-pin 12V power supply. given in the article of the same name. We closed the wires with numbers 15 and 16. And here is how the numbering itself goes:

Two (usually orange at the edges) in the opposite row from the green - 1 and 2 . And so on from left to right. The numbering of the next row is also from left to right. Look at the photo.

We insert the black probe of the device for a long time into the contact of the black connector (this will be the contact 3 ). It is located just opposite the black contact. 15 occupied by a scraper. In the language of specialists, this is called “putting the probe on the ground”, we will not remove it from the connector for the duration of the measurements (you can fix it there, just don’t overdo it):

With the red probe of the device, we will alternately check the value of the output voltage on all channels of the block (I say right away - the experimental power supply is healthy) and start with 1 th:

The second pin of the connector shows the same parameters:

Next tested contact number 4 - it's 5 volts. Check ( do not burn yourself on the scraper!):

Etc. And thus, from contact to contact, you must gradually compare the passport pinout readings of the PSU (see link above) with the readings of the device. That is, the readings of the multimeter will approximately coincide (with a small error) with the readings in the article table. Please note that contact 3 with contacts 5 , 7 , 17 , 18 , 19 , 24 the device should not respond.

ATTENTION . The next step we will try to check the power supply under load. All measurements just taken will be carried out in the same way, but with the connector connected to the board. When I made such measurements for the first time, I partly numbered (so as not to get confused) the wires on the connector with tape tags. I advise you too. Everything is not needed - just note the starting point and the order of counting. The color of the wire will remind you of the voltage indicators.

Check power supply under load

If the voltage values ​​​​of the pinout table and the readings of the multimeter when the PSU is idling are the same (measurement errors within fractions of a percent are acceptable and better upwards), let's try to check the power supply under load. Let's assemble the circuit by connecting all the cables, and put the computer into operation. DO NOT CLOSE THE LID YET! We need BIOS and type tab power with paragraph Hardware Monitor(There are many BIOS versions, their interface is different - so do not blame me). I have so:

The tab displays voltage values ​​as BIOS sees them. As you can see, the read information matches the measured ones. The power supply is working properly. And now it’s worth checking the indicated readings on the screen with the readings of the multimeter when working under load. We insert the PSU connector into the “mother” connector of the motherboard, connect all the devices, turn on the computer and check with the device in the same order, also successively changing the probes in the set measurement range, but in this manner:

I think I helped you draw some conclusions about the performance of the power supply. Of course, all these conclusions are superficial, and the cleanliness of the PSU can only be said armed with an oscilloscope.

Hello dear reader! In this article, we will Stress test computer for stability program OCCT (OverClock Checking Tool) at the time of this writing, the most recent version is 4.4.1.

With the help of the program OCCT we will be able to test the following components of our PC:

Program OCCT when passing the test, it gives the maximum load on the tested components of our PC. And if the testing ended without errors, then your PC and cooling system are fully functional, and they are not going to fail yet!

First, download the program, or from the official site, install.

The installation is standard, after running the downloaded installation file, in the first window, click "Next", in the second click "Accept", in the third "Next" and in the fourth window - the button "Install"

After installation, you will see the following program icon on your desktop OCCT

We launch the program from the shortcut. And before us appears something like this window.

Why about? Because the program window changes depending on the settings, I have already configured the program, and in the end, after all the settings, you will get the same program window, and then you will change it according to your interests.

So, let's start setting up the program OCCT.

In the main window of the program, click on this button

Getting into the settings window

In this window, the most important thing is to set the temperatures at which the test will be stopped, this is necessary to prevent the failure of any node from overheating.

ADVICE- If you have a fairly new PC, then the temperature can be set to 90 ° C. The components of the latest releases have rather high operating temperatures.

But if your PC is 5 or more years old, then set the temperature to 80 ° C. Later production parts are very sensitive to overheating.

The best option is to look at the maximum allowable temperatures of your iron on the manufacturer's website.

Components in overclocking do not pass the test! Program OCCT gives such a load that the temperature exceeds 90 ° C and stops the test.
90°C to 100°C and above is the critical point at which parts on your components will start to desolder from their seats if they don't burn out first.

But you should not be afraid to burn the system in panic! “I repeat” The main thing is to check all fans (Coolers) for operability before passing the test in the system block and clean the cooling system from dust.

And to spend computer stability test a must! To crash your PC (let's say at the time of writing some archi-important material for you) didn't come as a surprise.

After solving the issue of temperatures, in the last column of settings called "Real-time", we check the boxes for the graphs that we want to see when passing the test.

So, with the settings figured out, you can close them. Now let's go back to the main window of the program.

There are four tabs in the main program window. CPU:OCCT, CPU:LINPACK, GPU:3D and POWER SUPPLY.

Processor, RAM, and Motherboard Test - CPU:OCCT

Let's start with the values ​​here: For convenience, I numbered them.

1. Type of testing: Infinite - The test will run without time until you stop it yourself. Auto - The test will run according to the time set in paragraph 2. Duration.

3. Periods of inactivity– Time before the start of the test, and after the end. The report of which you will see in the program window after starting the test.

4. Test version- The capacity of your system. My program itself determined the bit depth at the first start.

5.Test Mode- Here we select one of the three sets in the drop-down menu: Large, Medium, and Small.

• Big set – Tested for errors Processor, RAM, and Motherboard (chipset).
• Medium set – Tested for errors Processor and RAM.
• small set– Only the Processor is tested for errors.

6. Number of threads- Set the number of threads that your processor supports. My program itself determined the number of processor threads.

Go to the second tab CPU:LINPACK

CPU Test - CPU:LINPACK

On points 1. 2. 3. I think everything is clear. See above in the first test

Point 4. We leave it unchanged.

5. Check the box if you have a 64-bit processor and system.

6. AVX is Linpack compatible. This parameter is determined for each processor separately.

I will not describe the microarchitecture of processors completely here, this is a separate topic, and I think it will be interesting for every user to delve into it.

7. Use all logical cores - Check the box so that our processor uses its full potential, including logical cores (if any).

Everything is clear here, let's move on to the next tab.

Video card test - GPU:3D

On points, everything is unchanged 1. 2. 3. I think everything is clear. See above in the first test

4. Install the version of DirectX that your Windows supports.

DirectX 9- shader model 2.0 Windows XP and older windows
DirectX 11- shader model 5.0 Windows Vista, Windows 7, Windows 8

5. Choose your video card.

6. Set the resolution of your monitor.

7. Put a tick. If you, like me, have 2 video cards installed in SLI mode.

8. If the checkbox is checked, then the heating of the video card will be lower, and error detection will be more efficient.

9. Uncheck the box if we want to use all the memory of the video card.

10. For video cards from Nvidia, a value of 3 is better. For video cards from ATI, a value of 7.

11. Set the number of frames per second. The value 0 is off. You can set the value to "0" to check how much FPS your video card can give.

Here, too, everything is set up, go to the last tab - POWER SUPPLY

PSU (Power Supply) Test

The settings are almost the same as on the tab GPU:3D

Here the principle of the test is as follows: The whole system operates at its fullest possible power, trying to strain our PSU to the maximum.

P.S. in the settings at the bottom of the main program window there is a field where hints appear when you hover over a custom item

You, like most personal computer users, have probably already encountered various problems associated with the failure of any vital configuration components. Just such details directly relate to the PC power supply, which tends to break down with an insufficiently high level of care from the owner.

In the framework of this article, we will consider all the currently relevant methods for checking PC power supply elements for operability. Moreover, we will also partially address a similar problem encountered by laptop users.

As we said above, a computer power supply, regardless of other assembly components, is an important detail. As a result, a breakdown of this component can lead to the complete failure of the entire system unit, which makes diagnostics much more difficult.

If your PC does not turn on, it may not be the PSU's fault at all - remember this!

The whole difficulty in diagnosing such components lies in the fact that the lack of power in the PC can be caused not only by the PSU, but also by other components. This is especially true of the central processor, the failure of which manifests itself in a huge variety of consequences.

Be that as it may, diagnosing problems in the operation of a power supply device is an order of magnitude easier than with malfunctions of other elements. This conclusion is due to the fact that the component in question is the only possible source of energy in the computer.

Method 1: Checking the power supply

If at any time during the operation of your PC you find it inoperative, you should immediately check the presence of electricity. Make sure the network is fully functional and meets the requirements of the power supply.

Sometimes power surges can occur, but in this case, the consequences are limited to turning off the PC on its own.

It will not be superfluous to double-check the PSU connection cord to the network for visible damage. The best test method would be to try connecting the used power cable to another fully working PC.

In the case of using a laptop, the steps to eliminate the presence of problems with electricity are completely similar to those described above. The only difference here is that in the event of a malfunction with the laptop cable, its replacement will cost an order of magnitude more expensive than in case of problems with a full-fledged PC.

It is important to carefully inspect and check the power source, whether it be an outlet or a surge protector. All subsequent sections of the article will focus specifically on the power supply, so it is extremely important to solve all the problems with electricity in advance.

Method 2: Using a jumper

This method is ideal for initial testing of the PSU for its performance. However, it is worth making a reservation in advance that if you have never interfered with the operation of electrical appliances and do not fully understand the principle of PC operation, the best way out is to contact technical specialists.

If any complications occur, you can put your life and the condition of the PD in serious danger!

The whole point of this section of the article is to use a manually made jumper to subsequently close the contacts of the power supply. It is also important to note here that the method is very popular among users and this, in turn, can greatly help if there are any inconsistencies with the instructions.

Before proceeding directly to the description of the method, you will need to disassemble the computer in advance.

You can learn a little more about turning off the PSU from a dedicated article.

Having dealt with the introduction, you can proceed to the diagnosis by using a jumper. And right away it should be noted right away that in fact this method has already been described by us, since it was created primarily to be able to start a power supply unit without using a motherboard.

After familiarizing yourself with the PSU start-up methodology given by us, after power is supplied, you should pay attention to the fan. If the main cooler of the device does not show signs of life, you can safely conclude that it is inoperable.

A broken power supply is best replaced or sent to a service center for repair.

If after starting the cooler works properly, and the PSU itself makes characteristic sounds, it can be said with a high degree of probability that the device is in working order. However, even under such circumstances, the guarantee of verification is far from ideal and therefore we recommend that you make a more in-depth analysis.

Method 3: Using a multimeter

As can be seen directly from the name of the method, the method consists in using a special engineering device "Multimeter". You will first need to acquire such a meter, as well as learn the basics of its use.

Usually among experienced users, the multimeter is referred to as a tester.

Refer to the previous method after completing all test instructions. After that, making sure that it is working and keeping open access to the main cable of the power supply, you can proceed to active actions.

1. First you need to find out what kind of cable is used in your computer. In total there are two types:

• 20-pin;
• 24 pin.

Don't forget to use hand protection!

As in the earlier method, after power is supplied, the PSU may not start, which directly indicates a malfunction. If the cooler still works, you can proceed to more detailed diagnostics by using a tester.

All values ​​given are roundings of these figures, since slight differences may still be due to certain circumstances.

After completing our instructions, make sure that the received data complies with the voltage level standard. If you notice significant enough differences, the power supply can be considered partially faulty.

The voltage level supplied to the motherboard is independent of the PSU model.

Since the PSU itself is a rather complex component of a personal computer, it is best to contact specialists for repairs. This is especially true for users who are not familiar with the operation of electrical devices.

In addition to the above, a multimeter may well come in handy in the process of checking a laptop's network adapter. And although breakdowns of this type of PSU are rare, you can all find problems, in particular when using a laptop in rather harsh conditions.

The laptop model has absolutely no effect on the level of electricity supplied.

In the absence of these indicators, you need to carefully examine the network cable again, as we said in the first method. In the absence of visible defects, only a complete replacement of the adapter can help.

Method 4: Using a power supply tester

In this case, you will need a special device for testing the PSU for analysis. Thanks to such a device, you can connect the pins of PC components and get results.

The cost of such a tester, as a rule, is somewhat lower than that of a full-fledged multimeter.

Please note that the device itself may differ significantly from the one presented by us. And although power supply testers come in different models that differ in appearance, the principle of operation is always the same.

1. Read the specification of the meter you are using to avoid difficulties.



2. Connect the appropriate wire from the PSU to the 24-pin connector on the case.



3. Depending on personal preference, connect the other pins to the dedicated connectors on the case.



4. It is recommended to use the Molex connector without fail.



It is also advisable to add voltage from the hard drive using the SATA II interface.

5. Use the power button of the measuring device to take readings of the PSU.



The button may need to be pressed briefly.

6. On the screen of the device, you will be presented with the final results.



7. The main indicators are only three:

• +5V - from 4.75 to 5.25 V;
• +12V - from 11.4 to 12.6 V;
• +3.3V - from 3.14 to 3.47 V.

If your final measurements are below or above the norm, as mentioned earlier, the power supply requires immediate repair or replacement.

Method 5: Using System Tools

Including cases when the PSU is still in working condition and allows you to start the PC without any special difficulties, you can perform troubleshooting using system tools. At the same time, note that checking is mandatory only when there are obvious problems in the behavior of the computer, for example, spontaneous turning on or off.

There is a lot of discussion around the issue of choosing a processor, video card or motherboard, but few people know that all this will not work correctly without a good power supply. This part converts the incoming voltage and distributes it to all elements of the computer. If the "machine" does not turn on, the first thing to check is the PSU.

How to check the health of the computer's power supply

A power supply failure is extremely rare, because all modern models have protection against power surges, overloads and other network problems that could disable it. However, if the computer does not turn on, the first place is not to check the processor, but to test the power supply. As a rule, if there are problems with it, the system unit does not show any signs of life: there is no rotation of the fans, noise from the hard drive or motherboard.

To test the power supply, you need to turn off the computer, on the back of the PSU, switch the toggle switch to the “off” position. For the convenience of work, the part must be removed from the system unit. As a rule, the power adapter has an atx format, which is standard for most case models, and a set of cables for the motherboard, video card, coolers, hard drive. They should be checked for serviceability first.

Power pin connectors

Checking the computer for operability begins with the presence of power supply to all elements of the system. To test the power pin connectors, the PSU will definitely need to be turned on, but for this it is not necessary to connect the part directly to the motherboard or anything else. To do this, a paper clip is enough to close the circuit or cooler, the main thing is that the power supply does not work “idle”.

If you have connected a cooler, then you can not be afraid to turn on the power supply. In the instructions or on the packaging, and often on the device itself, it is written what voltage should be applied to the lines. Using a multimeter, you can check each for compliance with the declared indicators. If somewhere the power does not match or the indicator is completely absent, this is the place where the PSU breaks down. This method will be described in more detail in the method for checking the motherboard power cable.

Computer power cable

In some cases, the cause of the breakdown is not one of the cables of the power supply, but the power cord that supplies voltage to the device. It can break when it is in the wrong position for a long time, burn out in places where the wire is exposed, etc. Replacing this element of the system is the easiest, so when checking the computer's power supply, they simply try to turn it on. For this you need:

1. Connect the cooler as described above so that there is a load.
2. If there is no cooler, then two contacts must be closed on the 24Pin (atx) cable.
3. Locate the green wire and the black wire that will need to be shorted.
4. Take an ordinary paper clip, unbend it to make the letter U.
5. Insert one end of the paper clip into the green wire and the other end into the black wire. This will tell the PSU that it is connected to the motherboard and allow it to turn on.
6. After that, you can turn on the device.
7. If the cooler of the device starts spinning, it means that power is being supplied to it, and the problem is not in the power cord.
8. If it does not spin, then the cable or some part inside the computer power supply itself is faulty.

Motherboard power

To check, you need a 24Pin (atx) cable that connects to the motherboard. It is not difficult to find it, it is the largest and has 24 pins (the old 20). A paperclip is already installed on it, if you did not connect the cooler. All the wires of this cable are painted in different colors, not for the sake of beauty, they indicate specific indicators. The colors mean the following:

• black - earth;
• orange - + 3.3V;
• red - +5V;
• yellow - +12;
• green - PS ON (paired with the "ground" starts the power supply unit, so they are closed by a paper clip);
• gray - +5V;
• purple - + 5V;
• white - -5V;
• blue - -12V;

Depending on the manufacturer, brand of computer power supply, these values ​​\u200b\u200bmay differ slightly, but most devices correspond to the above characteristics. You will need a multimeter to test the wires. One probe (negative, black) must be connected to the black wire, and the second (red) to the contact being tested. You must compare the declared voltage (by color) with the actual voltage. If significant discrepancies are observed somewhere, then this wire can serve as the reason for the incorrect operation of the PSU.

Checking the capacitor with a multimeter

The main task of this power supply element is to maintain, maintain an electric charge and smooth the voltage in the electrical circuit. For example, everyone has observed the “flashing” of light, which is essentially a short-term voltage drop in the network. Power supplies with faulty or bad capacitors cannot withstand such moments, the computer reboots. The good ones at this moment release the accumulated energy and provide enough tension to continue the operation of the system. You can check the capacitor as follows:

1. To check the capacitor, you must set the multimeter to the "ringing" mode.
2. If there is none, then to measure the resistance with the set value of 2 Kiloom.
3. Attach the black probe to the negative leg of the capacitor, and the red one to the positive one. If you mix it up, then nothing terrible will happen, but you won’t be able to check it either.
4. If everything is done correctly, then the capacitor will begin to charge. The indicator should be above 2M, which indicates sufficient capacity of the part and its serviceability. If the indicator is lower than or equal to 2M, the capacitor must be replaced.

How to test a resistor with a multimeter

The above describes in detail how to check the cables of the computer power supply, but the breakdown does not always lie in them. Sometimes smaller parts, such as resistors, are the cause of the failure. A burnt part can be detected with the naked eye, but sometimes the problem lies in incorrect resistance. To check you need:

1. Turn on the multimeter in resistance measurement mode.
2. View the nominal value either on the resistor itself or on the board next to it. If this data is not available anywhere (Chinese manufacturers put colored circles), then you can set the value to 2000 ohms, and if it is exceeded, the number 1 will simply appear.
3. Set the black probe to "minus" and the red probe to the "plus" of the resistor.
4. If the nominal and actual resistance do not match, the part must be replaced.
5. Deviations of 5% are allowed.

Computer power supply test program

How to check the power supply of a computer with a multimeter is understandable, but there is an option without having to remove it from the system unit. You can download a program with which you can check the PSU. It is used, as a rule, for spontaneous shutdowns, reboots, "blue screens of death". Before manually diagnosing, it is important to understand what specifically causes such failures. In some cases, the processor or driver is the cause. You can use the OCST program to check.

This software creates the maximum load on a particular element of the system. It is not recommended to use the program on cheap, weak systems. Inside it there are several tabs that relate to the processor and memory, video card and power supply. The load on a specific element will determine the problem with it. You need to do the following:

• go to the "power supply" tab;
• set the appropriate resolution for your monitor;
• test type - "manual";
• duration of the check - 1 hour;
• shader complexity - the optimal parameter offered by the program;
• check the boxes next to the boxes “full screen”, “hypertrading”, “64 bit Linckpad”;
• press the "ON" button.

If failures occur during the test, the program compiles a report on the errors that have occurred, indicates their nature, which allows you to work with specific problematic elements of the computer. This becomes a serious reason to remove the PSU and manually check it in detail with a multimeter. Remember that if you disassemble the part yourself, the warranty obligations from the manufacturer are removed.

Video: Checking the PC Power Supply

A very common cause of a personal computer malfunction is the failure of the power supply. The main symptom will be the fact that your computer won't turn on.

In order to confirm the failure of this part of the computer, you need to test the power supply. Let's consider several methods for such a check (they are no more difficult than the methods for checking RAM).

The main function of the power supply is to convert the incoming voltage to the required value.

Checking with a paperclip

The easiest way to check the power supply is to use a regular paper clip. As part of this method, we will try to turn on the power supply without a computer and check if it works.

To do this, you will need a paper clip, a power supply and a device for the load. After disconnecting the computer from the network, you must remove the power supply. As a load, you can use a standard 80-mm cooler or an optical drive. (if there is one in the system unit). It is also possible to use them together.

We connect the power supply and in the largest 24-pin connector we look for a contact with a green and black wire. There is more than one black wire, so you can use any. Usually use the contact that is nearby.

The closure must be done short. If the power supply is still working, then the fan of the power supply itself, as well as the 80-mm one, will begin to rotate. The connected drive will signal with a green light. If none of this happened, then the power supply is faulty.

visual inspection

If the power supply's warranty period has already expired, then an internal visual inspection can be carried out, which can clearly confirm the malfunction of this device. Before starting disassembly, be sure to disconnect the power supply from the mains! After removing the cover, you can see the following picture:

In this case, no additional devices are needed to determine the fault. In the last hours of operation of such a PSU, you could hear the smell of burning. Overheating and subsequent failure can also be caused by a malfunction of the cooling system. As a rule, this is a characteristic disease of cheap Chinese power supplies.

The presence of one or more "swollen" capacitors will also confirm a malfunction. But not always replacing them can restore performance. It is necessary to pay attention during such an inspection to the protection element - the fuse. If it is burned out, then the power supply can start only after replacing it.

Block failed:

Checking with additional equipment

There are more complex ways to check. The first method is characterized by using a multimeter to measure the output voltages. The simplest pointer or digital measuring device that you need to be able to use will do.

In addition, you need to know the allowable voltage outputs of the power supply. Finding them on the Internet is not difficult. Depending on the obtained indicators, it will be possible to determine the health of the power supply. Particular attention should be paid to the standby voltage. This is the red wire.

A device for testing power supplies has recently appeared on the market. (tester) It greatly facilitates the receipt of voltage readings. It is only necessary to connect all the main connectors and the actual output indicators will be shown on the display of the device.

At the same time, you need to work with such a device carefully. If the connectors are connected incorrectly, the power supply may not be damaged, but the tester can be guaranteed to fail. You need to be extremely careful. We compare the obtained data with the nominal indicators, which in the end will confirm the operability of the power supply or its absence.