How to check the power supply for functionality without a computer. Design features of power supplies

If a computer problem occurs, all systems must be checked. The user should know how to check the computer's power supply.

A computer, like any other equipment, is susceptible to various breakdowns. When operational problems occur, identifying their causes sometimes requires testing of almost all systems that ensure the operation of this complex device. Very often problems are primarily related to the power supply.

About computer power supplies

The computer's power supply supplies energy to all of its boards and devices, converts the voltage received from the network into values suitable for them, and reduces interference created by the network voltage. That is, the power supply is the most important part of any computer and its malfunctions affect the operation of the computer as a whole. If the power supply fails, other systems, such as a video card or motherboard, may fail. That is why, if any problems arise (problem with turning on the system unit, problem with cooling, etc.), it is recommended to check the operation of this particular unit first. And only then you can start checking other systems, for example, the processor. By the way, you can read about checking the processor’s operation in the article “”. You can check the power supply yourself.

How to check the power supply

Before checking, of course, you need to turn off the computer, including from the outlet. After this, remove the protective casing from your system unit and disconnect the 20-pin (or 24, depending on the type of power supply) plug coming from the power supply from the motherboard. Please note that the PS-ON contact must be connected to this plug - this is a green wire (standard).

It is most convenient to check the power supply when it is completely removed from the system unit. To check the power supply, you will have to turn it on, but it must be under load. That is, some device must be connected to it. You can connect a cooler - a cooling fan that is found in any computer. The fan is connected with a special connector and this procedure should not cause any difficulties. Yes, don’t be afraid to confuse the plus with the minus. Even if this happens, nothing will burn.

Next, the power supply must be turned on by closing the PS-ON contact with any other adjacent contact, for example, with the black wire. This is done using a regular paper clip or a piece of wire with stripped ends. The ends are inserted into the corresponding contacts on the plug. After this, the power supply is connected to the network. If it is working, and you did everything correctly, then the cooler should start spinning. If you did everything correctly, but there was no switching on, then your power supply is broken.

It happens that the turned on power supply still works with problems. In this case, there are two options:

Check the voltage at the contacts (use a multimeter). The operating voltage on different contacts is indicated on the sticker on the PSU body
Take it to a service center

For those who decide to carry out the check themselves, this video will be useful:

Failure of computer power supplies is a fairly common occurrence. The most unpleasant consequence may be the failure of components of the computer system unit, the power of which directly depends on the smooth operation of the power supply.

There can be many reasons for malfunctions: for example, if you have been using the source for quite a long time or the operating conditions are unfavorable - the lack of additional protection for voltage surges. The harmful effects are strong dustiness the environment in which he works is high temperature And humidity.

Basic obvious signs, those that are immediately visible:

the computer does not turn on;
burning smell in the BP area;
the body “shocks” with current.

However, there may be cases when it is not immediately clear whether the block is the cause of all the troubles:

sudden freezing And reboot PC (most often occurring during voltage sags);
work failures components such as a hard drive, due to the lack of supply voltage at the source outputs;
suddenly starts temperature rise in the case, the cooling fans stop working;
any errors when you turn on the computer.

These are the main, but not all, signs of malfunctions encountered today.

How to check the power supply

You can check your power supply yourself by first turning off the power, by visual inspection, using a paper clip and using a multimeter.

Visual inspection

Start the diagnosis by carefully examining your source inside, having disassembled it, begin research on defective components.

Pay attention to electrolytic capacitors, is there any among them swollen? Didn't it burn out? fuse, are there any obvious burnt elements, what is the condition of the input filters? Replace the suspect components, remembering to maintain the correct polarity (in the case of Conders).

Often, in cheap sources, in order to reduce the cost, instead of electrical filters, they simply install jumpers(as in the picture above). This may cause some problems.

Check with a paper clip

You can check your power supply without connecting a load. To do this, one paperclip or just a piece of wire will be enough to short-circuit 2 pins of the ATX output - 4 and 5th - green and black.

Below are pinout and a photo of what it looks like.

Having connected the power supply to the network, with such a short circuit this will be enough to start it without a motherboard, for checks. However, such a connection undesirable, due to possible failure without load, so be careful not to overload your source.

We use a multimeter

If you have a multimeter with thin probes, you can diagnose output voltages.

To do this, we “throw” the black probe onto the ground ( pin GND). And in red we check the voltages one by one according to table below(ATX standard has two versions).

That is, hooking the red probe to purple The pin shown in this pinout (9th) should receive a constant output voltage of +5V + 5%.

TO green(pin 14) – about +3.3V + 5%. TO yellow(10th) - +12V + 5%, to blue -12V + 5% and so on.

If you are not sure of what you are doing, don't do it. Otherwise, in this way you can check the power supply circuits, test the motherboard for breakdowns, and conduct more in-depth investigations of faults.

As you can see, the simplest test of the power supply for functionality does not require any special skills or abilities, but care and caution are required.

The power supply is an important component of the system, and without it the computer simply cannot work. It provides the required electrical energy to all consumers inside the computer case, while converting the AC voltage coming from the outlet into DC. When choosing a power supply for a computer, you need to be guided by its power, based on the number of consumers that will be connected to it. If the power supply fails, the entire computer will not work. That is why, if the computer stops turning on, it is important to check the power supply for functionality, and there are several ways to do this.

We recommend reading:

Signs of a faulty power supply

There is no specific symptom by which one could say that the power supply in the computer has failed. There are a number of signs that are typical for the behavior of a computer when the power supply fails. It can be stated that the power supply is not working properly (or there is another problem) with the following “behavior” of the computer:

When you press the power button, nothing happens, that is, there is no light or sound indication and the coolers do not start rotating. Since the power supply is a component that supplies other elements with constant voltage, there is a high probability that it has failed or there are other problems with the transfer of power to the computer elements - breaks in the wires, unstable supply of alternating voltage from the network;
The computer does not always turn on the first time. In such a situation, the power supply, poor connection of connectors or a malfunction of the power button may be to blame;
The computer turns off spontaneously while loading the operating system. This may occur due to intermittent voltage transfer from the power supply to other computer components. Also, a similar problem may indicate overheating of the power supply and forced shutdown.

The power supply is a reliable element of a computer that rarely fails. If the power supply is broken, the reason for this is its poor manufacturing quality or the supply voltage through the network with constant fluctuations. In addition, the power supply may fail if the calculation is made incorrectly when selecting it for a specific computer configuration.

How to check the power supply

If your computer has one of the symptoms listed above, you should not immediately blame the power supply. A malfunction may also occur for other reasons. To make sure there are problems with the power supply component of the system, it is necessary to carry out diagnostic work. There are 3 methods for checking your computer's power supply yourself.

Step 1: Check the Power Supply Transmits Voltage

To ensure that the power supply turns on, you must perform the following test:

It should be noted that this test shows the functionality of the power supply to turn on. But even if, according to its results, the cooler of the power supply begins to rotate, this does not mean that the device is fully operational. Proceed to the next steps to check the power supply.

Step 2: How to Test the Power Supply with a Multimeter

If you are sure that the power supply receives voltage from the network and is working, you need to check whether it supplies the required constant voltage. To do this:

Connect any external resistance to the power supply - floppy drive, hard drive, coolers;
Next, take a multimeter set to measure voltage and connect the negative lead of the diagnostic tool to the black pin of the 20/24-pin power supply connector. When connected in this way, the black contact is considered grounding. Connect the positive probe of the multimeter one by one to the connector contacts to which wires of the following colors are suitable, and also compare the values with the ideal voltage:

During measurement, errors of ±5% are possible.

If the measured values differ from the ideal values, you can diagnose a faulty power supply and the need to replace it.

Step 3: How to Visually Check the Power Supply

If you don’t have a multimeter (or if you need additional diagnostics), you can visually check the power supply for a malfunction. To do this:

When there are no problems with the capacitors, it is recommended to remove all dust from the power supply, lubricate the fan and reassemble the device, and then try to connect it.

The power supply is an integral part of any computer, and is no less important for operation than, for example, the processor or motherboard. Its main task is to generate the necessary currents for the operation of all PC components.

It often happens that the computer does not turn on, the operating system does not load, and a malfunctioning power supply may be to blame. How to check the PC power supply for functionality, what are the main clinical manifestations of some of its malfunctions - this is the main topic of our publication.

Main parameters of power supply

The PC power supply produces several voltages necessary for the operation of all components of the computer.

The picture shows the largest 20-pin connector that connects to the motherboard. Indications are given for each contact.

Pinout and color scheme of the 24-pin connector and other power supply connectors

Using a multimeter to check the power supply

Many users ask how to test a computer power supply with a multimeter? It’s very simple, knowing what voltage and where it should go.

Before opening the PC case, make sure that it is not connected to a 220 V network.

If the power supply is turned on, then you can start measuring the voltage at its contacts, according to the diagram presented above. If the computer's power supply does not turn on, it means that it is faulty and requires repair or complete replacement.

When checking with a multimeter, there should be - 5 V between the black and red wires on the connector connected to the motherboard; between black and yellow – 12 V; between black and pink contacts – 3.3 V; between black and purple - standby voltage is 5 V.

If you do not have sufficient knowledge in electronics, then it is better to entrust device repair to specialists.

Paperclip method

There is a simple method among users to check the power supply with a paper clip. Our resource will not stand aside and will tell you what this method is, especially since almost the same thing was discussed in the section on using a multimeter. This is the simplest, one might say, home method, which cannot show the quality of operation of the voltage source, but will reliably make it clear whether it turns on or not.

Disconnect your PC from the network.
Open the case and disconnect the connector from the motherboard.
Make a U-shaped jumper from a paper clip, which you need to short-circuit the green wire of the connector and the nearby black one.
Connect the power supply to a 220 V network.

If the fan starts working, then the power supply is theoretically in working order, if not, it’s definitely in repair.

Main symptoms and malfunctions

A faulty power supply, most often simply does not work at all. But sometimes, the user encounters problems that, by all indications, are manifestations of problems in the RAM or motherboard. In fact, the microcircuits receive power from the power supply, so failures in their operation may indicate a malfunction of the power supply. How to check the power supply in this case, and whether there is any point in repairing it, only a specialist can tell. Next, problems will be described in which the cause may be BP.

Freezes when turning on the PC.
Memory errors.
Stop HDD.
Stopping the fans.

There are also characteristic faults that the PC itself “speaks” about:

Not a single device works. The malfunction can be either fatal, requiring the purchase of a new device, or simple, requiring replacement of the fuse.
There was a smell of smoke. The transformer, chokes burned out, and the capacitors swelled.

The computer power supply is beeping. The fan may need to be cleaned and lubricated. A squeak when turned on is also caused by a crack in the transformer core and swelling capacitors.

In all cases, it is best to contact, where specialists will make a more accurate diagnosis and tell you whether there is any point in further repairing the device.

Good day, dear friends, acquaintances, readers, admirers and other individuals. Today we will test the computer through OCCT.

It is often necessary to find out the cause of problems, or simply any problems, from reboots/freezes to computer shutdowns.

In “field” (i.e., in normal working) conditions, this is not always possible, because some problems have a rather peculiar, so to speak, floating character and are not so easy to diagnose. And usually it’s not enough to just find out what is to blame, and not the software part, but you also need to understand what exactly is plotting, or rather what specific piece of hardware is faulty. In such situations, specialized software comes to our aid to check stability.

Do you want to know and be able to do more yourself?

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After launch, we will see a red one in front of us USSR-shaped program window (see screenshot above) in which, in theory, the Russian language should be immediately set. Before this, a window with a donation button may appear, for now you can close it (well, or immediately support the developer, it’s up to you).

If this is not the case, then click on the gear icon on the right, and then set the desired parameter. Or use it as is.

How to test a computer in general

The program has a set of tabs:

CPU:OCCT And CPU:LINKPACK, - testing processor stability under stressful conditions (load, power supply, temperature, etc.);
GPU:3D, - testing the stability of the video card;
POWER SUPPLY, - testing the stability of batteries (motherboard, power supply, circuits, etc., in general, load tests).

Let's try each of them, because each has its own parameters.

ATTENTION! Use with caution OCCT on laptops due to the high load and heating generated. On laptops with a weak/damaged cooling system (and other elements), this can lead to unpredictable consequences. Probably wise to use on them AIDA64.

Before the test, go to the above-mentioned settings (where you set the language) and set the processor temperature limiter (most often 85 too high value) and other (if necessary) components.

This is done as follows. We exhibit:

Test type: auto;
Test duration: 1 hour 0 minutes;
Test mode: Large dataset.

Comments on the items raised:

Runs for the specified time, i.e. an hour or more (or until an error is detected), allows you not to waste extra time on diagnostics;
Test time, is the test time;
Dataset, - determines the load level and the heat generated, as well as the number of elements being tested. If the data set is small, then only the processor is tested; if it is medium, then the processor + memory; if it is large, then the processor + memory + chipset. In a large set, the heating is stronger, but you can find more errors; in a small set, there is less heating, but you can miss something important;

Other parameters:

Inaction at the beginning and at the end - leave it as is, allows you to reduce the load before/after launch and read the necessary data;
Test version, - select the one that matches the installed version of the operating system;
Number of threads, - as a rule, a tick " is enough Auto", but if it is determined incorrectly (less than the number of physical and logical processor cores), then you can set it manually by unchecking it.

The second tab, namely CPU: LINPACK, is another test, but exclusively of the processor, and not of many elements at once (see the description of the first tab above).

Testing Warning

Worth with caution relate to this test, because it loads and heats up the processor extremely (including the core power supply, if supported by the motherboard) and is extremely extreme test. Recommended to use only in the presence of a powerful cooling system and an urgent need to diagnose it and the processor. In other cases, it is better to use the first test.

For those who have decided (usually required if the first test did not reveal problems, but “visually” they are preserved):

Test type: auto;
Test duration: 1 hour 0 minutes;
Test mode: 90% memory (I recommend closing all possible programs, etc., or reducing this value to 70-80%);
64 bit
AVX-compatible Linkpack

Then all you have to do is press the button ON and wait an hour (or less, if an error is found, the computer freezes, turns off, or shows some other signs of overheating and failure) while the system is scanned. The analysis of the results is described at the end of the article.

Supported Crossfire And SLI, checking and identifying many errors during strong heating during loads, and also, using a special system, artifacts (image distortions) are determined. You can do testing with different numbers of shaders, FPS and everything else.

Here, in fact, we present the following:

Test type: auto
Test duration: 1 hour 0 minutes
DirectX version
Permission
Type: full screen (checkmark);
Checking for errors: for the first test there is usually no need to check it, for the second (if the problem visually persists, but no errors are found) it makes sense to check the box;
Shader complexity: in general, this parameter is responsible for the number of operations performed by the video card in one pass (most often, the maximum available value is selected, or, if you need to specifically test for an application, then select the value that the application uses);
Limiter: 0 (zero), or 60 (if you use vertical synchronization and need to test the work for it).

The test itself looks usually like in the screenshot above. It does not start immediately (see periods of inactivity), it can change the type of picture (image). Significant visual distortions (it is difficult to confuse them with something else) are artifacts and indicate problems with the video card, its memory and something else.

ATTENTION! Quite complex to analyze, it is recommended to use it only if the first tests did not reveal anything in any way, but the problems persist. Dangerous and definitely not suitable for cheap ( noname) and low-quality power supplies. Use at your own risk.

Similar to the previous test, the following is set here:

Test type: auto
Test duration: 1 hour 0 minutes
DirectX version: if available, then 11, if not, then 9, if you need to specifically test for some application, then select the value that the application uses;
Permission: current, or, if you need to specifically test for some application, then select the value that the application uses;
Type: full screen mode (checkmark);
64 bit: if the system and processor support;
AVX-compatible Linkpack, - it makes sense to avoid if you don’t know what we’re talking about;
Use all logical cores, - must be checked if the checkbox is available (may not be available if they are not present or there is no access to them).

Analysis of test results OCCT

As a result of the tests, you can get the following result:

Charts, - most often, in the absence of a severe physical failure (shutdown, reboot, freeze, etc.), are the result of any test, contain temperatures, voltages and other data for analysis;
Error(in the program) - usually this is a kernel error or something else that stops the test (but the computer is working), most often its number or at least a brief description is indicated (kernel failure of such and such);
Blue screen of death, - that it makes sense to read;
Physical failure(or protection triggered), - shutdown, reboot, freeze and similar horrors of life.

How to take off with this;

For analysis temperature charts read (pay special attention to the maximum permissible values); if in doubt, see the documentation for the overheating component (paper, or on the manufacturer’s website) to analyze the maximum permissible temperatures;
For analysis nutrition-related charts, it is worth understanding that minor discrepancies are acceptable (tenths, hundredths, or less, orders of magnitude), excluding certain values (for example, processor power can change quite significantly due to energy saving technologies, frequency regulation, overclocking, etc.). If it’s difficult to figure it out, then contact us on the forum) for a more powerful one, or they (failures) are a consequence of a complete failure of the component. The latter are the most difficult to diagnose; most often, failures of the power supply (not completely turning off the computer or not turning on immediately) and/or video card (image artifacts) are immediately clear.

If complex problems arise that need to be sorted out by looking at graphs and so on, then contact us, for example, on the forum.

Afterword

I repeat that this is one of the most powerful stability tests that, in principle, can be found. It is quite often used by overclockers (those who overclock computer components) to check stability, which says a lot.

As always, if you have any (reasonable) thoughts, questions, thanks or additions, then, as usual, write them in the comments to this article (or on the forum mentioned above).

Thank you for being with us.
Stability to you!