Many PC owners face various errors and malfunctions of their computer, but they cannot determine the cause of the problem. In this article, we will look at the main methods of diagnosing a computer, allowing you to independently identify and fix various problems.
Please note that high-quality computer diagnostics can take a whole day, allocate it in the morning especially for this, and do not start closer to the evening.
I warn you that I will write in detail as for beginners who have never disassembled a computer, in order to warn about all possible nuances that can lead to problems.
1. Disassembling and cleaning the computer
When disassembling and cleaning your computer, do not rush, do everything carefully so as not to damage anything. Store the components in a safe place prepared in advance.
It is not advisable to start diagnostics before cleaning, since you will not be able to identify the cause of the malfunction if it is caused by clogged contacts or the cooling system. In addition, the diagnostics may fail to complete due to repeated failures.
Unplug the system unit from the outlet at least 15 minutes before cleaning to allow the capacitors to discharge.
Disassemble in the following sequence:
- Disconnect all wires from the system unit.
- Remove both side covers.
- Disconnect the power connectors from the video card and remove it.
- Take out all memory sticks.
- Disconnect and remove the ribbon cables of all drives.
- Unscrew and remove all discs.
- Disconnect all power supply cables.
- Unscrew and remove the power supply.
It is unnecessary to remove the motherboard, processor cooler, case fans, you can also leave the DVD drive if it works normally.
Carefully blow out the system unit and all components separately with a powerful air stream from a vacuum cleaner without a dust bag.
Carefully remove the cover from the power supply and blow it out without touching your hands and metal parts to the electrical parts and the board, as there may be voltage in the capacitors!
If your vacuum cleaner does not work for blowing, but only for blowing, then it will be a little more difficult. Clean it well so that it pulls as hard as possible. We recommend using a soft bristle brush when cleaning.
You can also use a soft brush to clean out any lingering dust.
Thoroughly clean the heatsink of the processor cooler, having previously considered where and how much dust it got clogged with, as this is one of the common reasons for processor overheating and PC crashes.
Also make sure that the cooler mount is not broken, the clip is not opened and the heatsink is firmly pressed against the processor.
Be careful when cleaning the fans, do not let them spin too much and do not bring the vacuum cleaner head close if it is without a brush, so as not to knock off the blade.
At the end of cleaning, do not rush to collect everything back, but proceed to the next steps.
2. Checking the motherboard battery
The first thing after cleaning, so as not to forget later, I check the battery charge on the motherboard, and at the same time I reset the BIOS. In order to pull it out, you need to press with a flat screwdriver on the latch in the direction indicated in the photo and it will pop out by itself.
After that, you need to measure its voltage with a multimeter, optimally if it is in the range of 2.5-3 V. The initial voltage of the battery is 3 V.
If the battery voltage is below 2.5 V, then it is advisable to change it already. The voltage of 2 V is critically low and the PC is already starting to fail, which manifests itself in resetting the BIOS settings and stopping at the beginning of the PC boot with a suggestion to press F1 or some other key to continue booting.
If you do not have a multimeter, you can take the battery with you to the store and ask to be checked there, or just buy a replacement battery in advance, it is standard and very inexpensive.
A clear sign of a dead battery is the constantly flitting date and time on the computer.
The battery needs to be replaced in a timely manner, but if you do not have a replacement at hand now, then simply do not disconnect the system unit from the power supply until you change the battery. In this case, the settings should not fly off, but problems can still arise, so do not delay.
Battery check is a good time to do a full BIOS reset. This resets not only the BIOS settings, which can be done through the Setup menu, but also the so-called volatile CMOS memory, which stores the parameters of all devices (processor, memory, video card, etc.).
Errors inCMOS are often the causes of the following problems:
- the computer does not turn on
- turns on every other time
- turns on and nothing happens
- turns on and off itself
Let me remind you that before resetting the BIOS, the system unit must be disconnected from the outlet, otherwise the CMOS will be powered by the power supply and nothing will work.
To reset the BIOS for 10 seconds, close the contacts in the battery connector with a screwdriver or other metal object, this is usually enough to discharge the capacitors and completely clear the CMOS.
A sign that the reset has occurred will be a misplaced date and time, which will need to be set in the BIOS at the next computer boot.
4. Visual inspection of components
Carefully inspect all capacitors on the motherboard for swelling and streaks, especially around the processor socket.
Sometimes capacitors do not swell up, but downward, which leads to their tilting, as if they were just bent a little or soldered unevenly.
If some capacitors are swollen, then you need to return the motherboard for repair as soon as possible and ask to re-solder all capacitors, including those that are next to the swollen ones.
Also, inspect the capacitors and other elements of the power supply, there should be no swelling, drips, traces of burning.
Inspect the disc contacts for oxidation.
They can be cleaned with an eraser and after that it is imperative to replace the cable or power adapter with which this disk was connected, since it is already damaged and most likely oxidation has occurred because of it.
In general, check all cables and connectors so that they are clean, with shiny contacts, tightly connected to the drives and the motherboard. All loops that do not meet these requirements must be replaced.
Check if the wires are properly connected from the front of the case to the motherboard.
It is important that the polarity is respected (plus to plus, minus to minus), since there is a total mass on the front panel and non-observance of polarity will lead to a short circuit, which may cause the computer to behave inadequately (turn on once, turn off or restart itself) ...
Where the plus and minus in the front panel contacts is indicated on the board itself, in the paper manual for it and in the electronic version of the manual on the manufacturer's website. On the contacts of the wires from the front panel, it is also indicated where the plus and minus are. Usually, the white wire is a minus, and the plus connector can be indicated by a triangle on the plastic connector.
Many even experienced collectors make a mistake here, so check it out.
5. Checking the power supply
If the computer did not turn on at all before cleaning, then do not rush to assemble it, the first step is to check the power supply. However, in any case, it will not hurt to check the power supply unit, it may be because of it that the computer crashes.
Check the PSU fully assembled to avoid electric shock, short circuit, or accidental fan breakage.
To test the power supply, short the single green wire in the motherboard connector with any black one. This will signal the PSU that it is connected to the motherboard, otherwise it will not turn on.
Then plug the power supply into the surge protector and press the button on it. Don't forget that the power supply itself may also have an on / off button.
A spinning fan should indicate that the power supply is on. If the fan does not spin, then it may be out of order and needs to be replaced.
In some silent power supplies, the fan may not start spinning immediately, but only under load, this is normal and can be checked during the operation of the PC.
Measure the voltage between the pins in the peripheral connectors with a multimeter.
They should be around the following range.
- 12V (yellow-black) - 11.7-12.5V
- 5V (red-black) - 4.7-5.3V
- 3.3V (orange-black) - 3.1-3.5V
If any voltage is absent or strongly outside the specified limits, then the power supply is defective. It is best to replace it with a new one, but if the computer itself is inexpensive, then repair is allowed, PSUs lend themselves to this easily and inexpensively.
The start of the power supply and normal voltages are a good sign, but by itself it does not mean that the power supply is good, since failures can occur due to voltage drops or ripple under load. But this is already determined at the subsequent stages of testing.
6. Checking power contacts
Be sure to check all electrical contacts from the outlet to the system unit. The socket must be modern (for a European plug), reliable and not loose, with clean elastic contacts. The same requirements apply to the surge protector and the cable from the computer's power supply.
Make sure the contact is secure and there must be no loose, sparking or oxidized plugs or connectors. Pay close attention to this, since poor contact is often the cause of failure of the system unit, monitor and other peripheral devices.
If you suspect the quality of the outlet, surge protector, power cable of the system unit or monitor, then change them as soon as possible to avoid damage to the computer. Do not delay and do not save on this, as repairing a PC or monitor will cost significantly more.
Also, poor contact is often the cause of PC malfunctions, which are accompanied by a sudden shutdown or reboot, followed by failures on the hard drive and, as a result, disruption of the operating system.
More failures can occur due to dips or voltage ripples in the 220 V network, especially in the private sector and remote areas of the city. In this case, crashes can occur even when the computer is idle. Try to measure the voltage in the outlet immediately after a spontaneous shutdown or restart of the computer and observe the readings for a while. So you can identify long-term drawdowns, which will save you from a linear-interactive UPS with a stabilizer.
7. Assembling and turning on the computer
After cleaning and inspecting the PC, carefully reassemble it and carefully check that you have connected everything you need. If the computer refused to turn on before cleaning or turned on every other time, then it is advisable to connect the components in turn. If there were no such problems, then skip the next section.
7.1. Phased PC assembly
First, connect the motherboard power connector and the processor power connector to the motherboard with the processor. Do not insert RAM, video card and do not connect disks.
Turn on the power of the PC and if everything is normal with the motherboard, the fan of the processor cooler should spin. Also, if a buzzer is connected to the motherboard, a beep code usually sounds, indicating the lack of RAM.
Install memory
Turn off the computer with a short or (if it does not work) long press of the power button on the system unit and insert one stick of RAM into the color slot closest to the processor. If all slots are of the same color, then just go to the one closest to the processor.
Make sure that the memory strip is inserted evenly, all the way and that the latches snap into place, otherwise it may be damaged when you turn on the PC.
If the computer starts up with one memory bar and there is a buzzer, then a code usually sounds, signaling that there is no video card (if there is no integrated graphics). If the beep code signals a problem with the RAM, then try to insert another bar in the same place. If the problem continues or there is no other bar, then move the bar to another nearest slot. If there are no sounds, then everything is possible, continue on.
Turn off the computer and insert the second memory strip into the slot of the same color. If the motherboard has 4 slots of the same color, then follow the instructions for the motherboard, so that the memory is in the slots recommended for dual-channel mode. Then turn it on again and check if the PC turns on and what beeps it emits.
If you have 3 or 4 memory sticks, then simply insert them in turn, each time turning off and on the PC. If the computer does not start with a certain bar or issues a beep memory error code, then this bar is faulty. You can also check the slots of the motherboard by moving the working bar to different slots.
Some motherboards have a red indicator that glows in case of memory problems, and sometimes a segment indicator with an error code, the decoding of which is in the manual for the motherboard.
If the computer starts, then further memory testing occurs at a different stage.
Installing a graphics card
It's time to test your graphics card by inserting it into the top PCI-E x16 slot (or AGP for older PCs). Do not forget to connect additional power to the video card with the appropriate connectors.
With the video card, the computer should start normally, without sound signals, or with a single sound signal, indicating a normal self-test.
If the PC does not turn on or emits a beep error code for the video card, then it is most likely faulty. But don't jump to conclusions, sometimes you just need to connect a monitor and keyboard.
Monitor connection
Turn off the PC and connect the monitor to the video card (or motherboard if there is no video card). Make sure that the connector to the video card and the monitor is firmly connected, sometimes tight connectors do not fit all the way, which causes no image on the screen.
Turn on the monitor and make sure that the correct signal source is selected on it (the connector to which the PC is connected, if there are several).
Turn on the computer and the graphic splash screen and motherboard text messages should appear on the screen. Usually this is a suggestion to enter the BIOS by pressing the F1 key, a message about the absence of a keyboard or bootable devices, this is normal.
If the computer turns on silently, but there is nothing on the screen, most likely something is wrong with the video card or monitor. The video card can only be checked by moving it to a working computer. The monitor can be connected to another work PC or device (laptop, player, tuner, etc.). Do not forget to select the desired signal source in the monitor settings.
Connecting a keyboard and mouse
If everything is fine with the video card and monitor, then move on. Connect the keyboard first, then the mouse in turn, each time turning off and on the PC. If the computer freezes after connecting the keyboard or mouse, then they need to be replaced - it happens!
Connecting drives
If the computer starts up with a keyboard and a mouse, then we begin to connect hard drives one by one. Connect the second non-operating system drive first (if available).
Do not forget that in addition to connecting the interface cable to the motherboard, you also need to connect the connector from the power supply to the disk.
Then turn on the computer and if it comes to BIOS messages, then everything is fine. If the PC does not turn on, freezes or shuts down by itself, then the controller of this disk is out of order and needs to be replaced or carried for repair to save the data.
Turn off the computer and connect the DVD drive (if any) with an interface cable and power supply. If problems arise after this, then the drive has a power failure and needs to be replaced; it usually does not make sense to repair.
At the end, we connect the main system drive and prepare to enter the BIOS for initial configuration before starting the operating system. We turn on the computer and if everything is fine, go to the next stage.
When you turn on your computer for the first time, enter BIOS. Usually, the Delete key is used for this, less often others (F1, F2, F10 or Esc), which is indicated in the tips at the beginning of the download.
On the first tab, set the date and time, and on the “Boot” tab, select your hard disk with the operating system as the first boot device.
On old motherboards with classic BIOS, it might look like this.
On more modern ones with a graphical UEFI shell, it is slightly different, but the meaning is the same.
To exit the BIOS while saving the settings, press F10. Do not get distracted and watch how the operating system is fully loaded to notice possible problems.
After the PC boots up, check if the fans of the processor cooler, power supply and video card are working, otherwise there is no point in further testing.
Some modern video cards may not turn on the fans until a certain temperature of the video chip is reached.
If any of the case fans do not work, then this is not a big deal, just plan to replace it in the near future, do not be distracted by it now.
8. Error analysis
Here, in fact, the diagnostics begins, and everything described above was only a preparation, after which many problems could go away and without it there was no point in starting testing.
8.1. Enabling memory dumps
If during the operation of the computer, blue screens of death (BSOD) appeared, then this can greatly facilitate the identification of the malfunction. A prerequisite for this is the presence of memory dumps (or at least self-written error codes).
To check or enable the dump recording function, press the "Win + R" key combination on the keyboard, enter "sysdm.cpl" in the line that appears and press OK or Enter.
In the window that appears, go to the "Advanced" tab and in the "Startup and Recovery" section, click the "Options" button.
The field "Write debug information" should be "Small memory dump".
If so, then you should already have dumps of previous errors in the C: \\ Windows \\ Minidump folder.
If this option was not enabled, then the dumps were not saved, enable it at least now to be able to analyze errors if they are repeated.
Memory dumps may not have time to be created during severe failures with rebooting or shutting down the PC. Also, some system cleaning utilities and antiviruses can delete them, you must disable the system cleaning function during the diagnosis.
If there are dumps in the specified folder, then proceed to their analysis.
8.2. Analysis of memory dumps
For analyzing memory dumps in order to identify what leads to failures, there is a wonderful utility "BlueScreenView", which you can download along with other utilities for diagnostics in the "" section.
This utility shows the files that crashed. These files belong to the operating system, device drivers, or some program. Accordingly, by the ownership of the file, you can determine which device or software was the fault of the failure.
If you cannot boot the computer in normal mode, try booting in safe mode by holding down the "F8" key immediately after the motherboard graphic splash screen or BIOS text messages disappears.
Go through the dumps and see which files are most often identified as the culprit of the failure, they are highlighted in red. Right-click on one of these files and view its Properties.
In our case, it is easy to determine that the file belongs to the "nVidia" video card driver and most of the errors were caused by it.
Besides, in some dumps the file "dxgkrnl.sys" appeared, even from the name of which it is clear that it refers to DirectX, directly related to 3D graphics. This means that it is most likely that the video card is to blame for the failure, which should be subjected to rigorous testing, which we will also consider.
In the same way, you can determine that the fault is a sound card, a network card, a hard drive, or some kind of program that deeply crawls into the system such as antivirus. For example, if a disk fails, the controller driver will crash.
If you cannot determine to which driver or program this or that file belongs, then look for this information on the Internet by the file name.
If the sound card driver malfunctions, it is most likely out of order. If it is integrated, then you can disable it through the BIOS and install another discrete one. The same can be said about the network card. However, network failures can be caused, which is often solved by updating the driver of the network card and connecting to the Internet through a router.
In any case, do not make hasty conclusions until the diagnosis is complete, maybe your Windows just crashed or a virus got in, which is solved by reinstalling the system.
Also in the "BlueScreenView" utility you can see the error codes and inscriptions that were on the blue screen. To do this, go to the "Options" menu and select the "Blue Screen in XP Style" view or press the "F8" key.
After that, switching between errors, you will see how they looked on a blue screen.
You can also find the possible cause of the problem on the Internet by the error code, but it is easier and more reliable to do this by file ownership. To return to the previous view, you can use the "F6" key.
If different files and different error codes appear in errors all the time, then this is a sign of possible problems with the RAM, in which everything is crashing. We will subject it to diagnostics in the first place.
9. Testing RAM
Even if you think the problem is not with the RAM, check it first anyway. Sometimes the place has several problems, and if the RAM fails, then it is quite difficult to diagnose everything else due to frequent PC crashes.
It is imperative to run a memory test from a bootable disk as it is difficult to get accurate results on a Windows operating system on a failed PC.
In addition, Hiren’s BootCD contains several alternative memory tests in case Memtest 86+ does not start, and many more useful utilities for testing hard drives, video memory, etc.
You can download the "Hiren's BootCD" image in the same place as everything else - in the "" section. If you do not know how to properly burn such an image to a CD or DVD disc, refer to the article where we examined, everything is done in the same way.
Configure BIOS to boot from DVD drive or use “Boot Menu” as described in, boot from “Hiren’s BootCD” and run “Memtest 86+”.
Testing can take from 30 to 60 minutes, depending on the speed and amount of RAM. One complete pass should be completed and the test will continue on the second round. If everything is normal with the memory, then after the first pass (Pass 1) there should be no errors (Errors 0).
After that, testing can be interrupted by pressing the "Esc" key and the computer will restart.
If there were errors, then you will have to test each bar separately, taking out all the others to determine which one is broken.
If the broken bar is still under warranty, then take a photo from the screen using a camera or smartphone and present it to the warranty department of the store or service center (although in most cases this is not necessary).
In any case, it is not advisable to use a PC with a broken memory and carry out further diagnostics before replacing it, since various incomprehensible errors will pour in.
10. Preparation for component tests
Everything else, except for RAM, is tested under Windows. Therefore, in order to exclude the influence of the operating system on the test results, it is advisable to do, if necessary, temporarily and the most.
If this is difficult for you or there is no time, then you can try to test on the old system. But, if failures occur due to malfunctions in the operating system, some driver, program, virus, antivirus (i.e. in the software part), then hardware testing will not help determine this and you can go down the wrong path. And on a clean system, you will have the opportunity to see how the computer behaves and completely eliminate the influence of the software component.
Personally, I always do everything as it should be from start to finish as described in this article. Yes, it takes a whole day, but ignoring my advice, you can beat for weeks without determining the cause of the problem.
The fastest and easiest way is to test the processor, unless of course there are clear signs that the problem is in the video card, which we will discuss below.
If your computer starts to slow down after a while after being turned on, freezes when watching videos, playing games, suddenly reboots or turns off under load, then there is a possibility of processor overheating. In fact, this is one of the most common causes of such problems.
During the cleaning and visual inspection stage, you had to make sure that the processor cooler is not clogged with dust, its fan rotates, and the heatsink is firmly pressed against the processor. I also hope that you did not remove it when cleaning, as this requires replacing the thermal paste, which I will talk about later.
We will use "CPU-Z" for a stress test with processor warming up, and "HWiNFO" for monitoring its temperature. Although, it is better to use a proprietary motherboard utility to monitor the temperature, it is more accurate. For example, ASUS has "PC Probe".
To begin with, it would be nice to know the maximum allowable thermal package of your processor (T CASE). For example, for my Core i7-6700K it is 64 ° C.
You can find out by going to the manufacturer's website from a search on the Internet. This is the critical temperature in the heat spreader (under the processor cover), the maximum allowed by the manufacturer. Do not confuse it with the core temperature, which is usually higher and is also displayed in some utilities. Therefore, we will focus not on the core temperature as measured by the processor sensors, but on the overall processor temperature as measured by the motherboard.
In practice, for most older processors, the critical temperature above which to fail is 60 ° C. Most modern processors can operate at 70 ° C, which is also critical for them. The real stable temperature of your processor can be found in tests on the Internet.
So, we launch both utilities - "CPU-Z" and "HWiNFO", find the processor temperature sensor (CPU) in the motherboard, run the test in "CPU-Z" with the "Stress CPU" button and observe the temperature.
If after 10-15 minutes of the test the temperature is 2-3 degrees lower than the critical one for your processor, then there is nothing to worry about. But, if there were failures at high load, then it is better to run this test for 30-60 minutes. If your PC freezes or restarts during testing, you should consider improving cooling.
Please note that much also depends on the temperature in the room, it is possible that in cooler conditions the problem will not manifest itself, but in hotter conditions it will immediately make itself felt. So there is always a need for oversized cooling.
In case of CPU overheating, check if your cooler is adequate. If not, then you need to change it, no tricks will help here. If the cooler is powerful enough, but does not cope a little, then you should change the thermal paste to a more effective one, at the same time the cooler itself may be installed more successfully.
From inexpensive, but very good thermal pastes, I can recommend Artic MX-4.
It should be applied in a thin layer, after removing the old paste with dry and then moistened with alcohol cotton wool.
Replacing the thermal paste will give you a gain of 3-5 ° C, if this is not enough, then simply add case fans, at least the most inexpensive ones.
14. Testing disks
This is the longest stage after the RAM test, so I prefer to leave it for last. To begin with, you can test the speed of all disks using the "HDTune" utility, to which I give "". This sometimes helps to identify freezes when accessing the disk, which indicates problems with it.
Look at the SMART parameters, where "disk health" is displayed, there should be no red lines and the general disk status should be "OK".
You can download a list of the main SMART parameters and what they are responsible for in the section "".
A complete surface test can be performed using the same utilities from under Windows. The process can take 2-4 hours, depending on the size and speed of the disk (about 1 hour for every 500 MB). At the end of the test, there should be no broken blocks that are highlighted in red.
The presence of such a block is an unambiguous verdict for the disc and a 100% guarantee case. Save your data and change the disk faster, just do not tell the service that you dropped your laptop
You can check the surface of both conventional hard drives (HDD) and solid-state drives (SSD). The latter really have no surface, but if the HDD or SSD disk freezes every time during the check, then the electronics are likely to fail - you need to change or repair (the latter is unlikely).
If you are unable to diagnose the disk under Windows, the computer crashes or freezes, then try to do it using the "MHDD" utility from the "Hiren's BootCD" boot disk.
Problems with the controller (electronics) and the surface of the disk lead to windows with errors in the operating system, short-term and complete freezes of the computer. Usually these are messages about the inability to read a particular file and memory access errors.
Such errors can be mistaken for problems with the RAM, while the disk may well be to blame. Before you panic, try updating the disk controller driver, or vice versa, return the native Windows driver as described in.
15. Testing the optical drive
To test an optical drive, it is usually sufficient to simply burn a verification disc. For example, using the program "Astroburn", it is in the section "".
After burning a disc with a message about successful verification, try copying its entire contents on another computer. If the disc is readable and the drive reads other discs (except for poorly readable ones), then everything is fine.
Drive problems that I encountered were electronics failures that completely hung up or prevented the computer from turning on, breakdowns of the slide mechanism, contamination of the laser head lens, and head breakage as a result of improper cleaning. In most cases, everything is solved by replacing the drive, since they are inexpensive and even if they have not been used for several years, they die from dust.
16. Checking the case
The case also sometimes breaks, then the button sticks, then the wires from the front panel fall off, then it closes in the USB connector. All this can lead to unpredictable PC behavior and is solved by careful inspection, cleaning, tester, soldering iron and other improvised means.
The main thing is that nothing is short-circuiting, which may be evidenced by a non-working light bulb or connector. When in doubt, disconnect all wires from the front of the case and try to work at the computer for a while.
17. Checking the motherboard
Often, checking the motherboard comes down to checking all the components. If all the components individually work fine and pass the tests, the operating system is reinstalled, but the computer still crashes, it may be the motherboard. And here I will not help you, to diagnose it and identify a problem with a chipset or processor socket only an experienced electronics engineer can do.
An exception is the crash of a sound or network card, which is solved by disabling them in the BIOS and installing separate expansion cards. Capacitors can be re-soldered in the motherboard, but, say, replacing the north bridge, as a rule, is not advisable to produce, since it is expensive and there are no guarantees, it is better to immediately buy a new motherboard.
18. If all else fails
Of course, it is always better to find the problem yourself and determine the best way to solve it, since some unscrupulous repairmen strive to hang on your ears and strip off three skins.
But it may be that you follow all the recommendations, but you will not be able to determine the problem, this happened to me. In this case, the matter is more often in the motherboard or in the power supply unit, maybe there is a microcrack in the PCB and it makes itself felt from time to time.
In this case, there is nothing you can do, take the entire system unit to a more or less well-established computer company. You do not need to carry components in parts if you are not sure what the matter is, so the issue will never be resolved. Let them figure it out, especially if the computer is still under warranty.
Specialists of a computer store usually do not bother, they have a lot of different components, they just change something and see if the problem is gone, thus quickly and easily fixing the problem. They also have enough time to conduct tests.
19. Links
Transcend JetFlash 790 8GB
Western Digital Caviar Blue WD10EZEX 1 TB Hard Drive
Transcend StoreJet 25A3 TS1TSJ25A3K
It turns out very easy - we take 20-pin connector from the power supply unit which actually connects to the "motherboard", we find green wiring and close it with any black wire. Oops, and it turns on in the unit - a fan starts spinning in it. Read on for more details.
More detailed information on computer power supplies:
How to check the performance of a PSU
Sometimes, when repairing a PC, it becomes necessary to check the performance of the PSU. How to do this without connecting the PSU to a PC?
To do this, connect some kind of load to the power supply (for example, CD-ROM or floppy drive), short-circuit the green and any black wires in the PSU connector (for example, with a paper clip) and turn on the PSU. On a working power supply unit, the fan will immediately start working and the drive LED (connected as a load) will turn on.
Most often, the diodes and transistors of the input power circuit and the fuse fail in the power supply unit.
20-pin connector
Used before PCI-Express motherboards
20-pin ATX connector (motherboard view)
5V VSB - "standby" 5V power supply (voltage is supplied when the computer is off)
... PW OK - Power (5V & 3.3V) OK
... PS ON - 14th contact in case of a short to ground (Gnd) - 15th contact power supply turns on, turns off when opened. (Do not turn on without load for a long time).
... Gnd - "ground"
Additional 4-pin ATX connector
With the advent of new Pentium 4 / Athlon 64 processors that use the 12V bus for their power supply (instead of 3.3 / 5V, as before), there is a need for an additional 12V connector to power them. This connector is usually located next to the processor socket, usually on top of the board.
24-pin connector
24-pin ATX connector (motherboard view)
It is used in power supply circuits for Pentium 4 and Athlon 64 processors with PCI Express bus.
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The 24-pin connector differs from the 20-pin connector only by 4 new pins (in the diagram - on the left), so in most cases it turns out to be compatible with older devices. |
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Options modern power supply unit.
The average power of modern power supplies is from 300 to 500 W, and the maximum has already exceeded 1 kWh.
The power supply unit generates the following voltages:
Main stabilized voltage +5 IN (current strength 10-50 AND);
12IN (current strength 3.5-15 AND) - to power the motors of devices and interface circuits;
12IN (current 0.3-1 AND) - for power supply of interface circuits;
5IN (current strength 0.3-0.5 AND) - usually not used, left for compatibility with the standard ISA Bus);
3,3IN - for food RAM.
Power supply circuits ATX have standardized color coding.
Color coding of the main power supply connector:
GND - black ("ground");
5V - red;
12V - yellow;
5V - white;
12V - blue;
3.3V - orange;
3.3V Sense - brown (serves to provide a feedback signal to the voltage stabilizer +3.3 IN);
5VSB - crimson ("watch" chain Standby);
PS-ON - green (control signal circuit that includes the main voltage sources +5, +3.3, +12, -12 and -5 IN);
PW-OK - gray (supply voltage signal circuit - Power OK).
Additional connector color coding:
3.3V Sense - white with brown stripes;
FanC - white with blue stripes (signal circuit for controlling the fan speed - supplying voltage 0 ... + 12 IN at amperage up to 20 mA);
FanM - white (signal from the BP fan tachometer sensor - two pulses for each rotor revolution);
1394V - white with red stripes (+ isolated from the circuit "ground" voltage source 8-48 IN for supplying bus devices IEEE-1394 [Firewire]);
1394R - white with black stripes (- isolated from the circuit "ground" voltage source 8-48 IN for supplying bus devices IEEE-1394 [Firewire]).
In modern PSU standard ATX voltage 220 IN present only inside the PSU case. At the same time, only a low voltage direct current is present inside the system unit (this is done for safety reasons).
PSU fan is powered from the network +12 IN.
The power management interface allows software power off (from the operating system via the Start etc.).
Computer won't turn on? In this material you will find the answer to the question: how to check the computer's power supply.
There is a thesis solution to this problem in one of our previous articles.
Read about how to check its performance in our today's article.
A power supply unit (PSU) is a secondary power source (the primary source is an outlet), the purpose of which is to convert alternating voltage to direct voltage, as well as to provide power to computer nodes at a given level.
Thus, the power supply unit acts as an intermediate link between the electrical network and, accordingly, the performance of the remaining components depends on its serviceability and correct operation.
Causes and symptoms of power supply failure
As a rule, the reasons due to which power supplies fail can be:
low quality of the mains voltage (frequent voltage drops in the mains, as well as its going beyond the operating range of the power supply unit);
low quality of components and manufacturing in general (this item is relevant for cheap power supplies);
It is possible to determine if a power supply unit or some other component is out of order by the following criteria:
after pressing the power button of the system unit, nothing happens - there is no light and sound indication, the cooling fans do not rotate;
the computer turns on every other time;
The power supply can be checked in several ways.
We will talk about the sequence of each of the checks below, but for now we will only limit ourselves to short information to understand what we will do.
The essence of the first method is to check the voltage supply and at this stage we perform a rough check - is there voltage or not.
The second way is to check the output voltage, we have already mentioned that the voltage must be strictly within certain limits and deviation in any direction is unacceptable.
The third way is to visually inspect the PSU for swollen capacitors.
For convenience, the algorithm for each of the checks will be presented in the form of step-by-step instructions.
Checking the power supply from the power supply
Step 1.
Step 2.
Remember, or for convenience, take a picture of how the power is connected to each of the components (motherboard, hard drives, optical drive, etc.) after which they should be disconnected from the power supply.
Step 3. Find a paper clip. With a paper clip, we will close the contacts on the power supply, and if it was not at hand, a wire similar to a paper clip in length and diameter will do.
After that, the paper clip must be bent in the form of the Latin letter "U".
Step 4. Find the 20/24 pin power connector. This connector is very easy to find - it is a bundle of 20 or 24 wires, respectively, that go from the power supply and were connected to the PC motherboard.
Step 5. Find the green and black wire connectors on the connector. A paper clip must be inserted into the connectors to which these wires are connected.
The paper clip must be securely fixed and make contact with the appropriate connectors.
Step 6.
Step 7. Power supply fan performance check. If the device is working and conducts current, then the fan located in the PSU case should rotate when voltage is applied.
If the fan does not rotate, check the contact of the paper clip with the green and black connectors of the 20/24 pin connector.
As mentioned above, this check does not guarantee that the device is working. This test allows you to determine that the power supply is turning on.
For a more accurate diagnosis, the following test should be performed.
Checking the correct operation of the power supply
Step 1. Turn off computer. It must be remembered that the power supply unit of the computer operates with a voltage dangerous to humans - 220V.
Step 2. Open the side cover of the system unit.
Remember, or for convenience, take a picture of how the power is connected to each of the components (motherboard, hard drives, optical drive, etc.) after which they should be disconnected from the power supply.
Step 3. Find the 20/24 pin power connector.
This connector is very easy to find due to its larger size - it is a bundle of 20 or 24 wires, respectively, that go from the power supply and were connected to the PC motherboard.
Step 4. Find the connectors for the black, red, yellow, pink wires on the 20/24 pin connector.
Step 5. Carry out the load of the PSU. In the future, we will measure the output voltage of the power supply.
In normal mode, the PSU operates under load, supplying power to the motherboard, hard drives, optical drives, and fans.
Measuring the output voltage of a PSU that is not under load can lead to a rather high error.
Note! The load can be an external 12V fan, an optical drive or an old hard disk drive, or combinations of these devices.
Step 6. Switch on the power supply. We supply power to the PSU (do not forget to turn on the power button on the PSU itself, if it was turned off in Step 1).
Step 7. Take a voltmeter and measure the output voltage of the PSU. The output voltage of the power supply unit will be measured on the pairs of wires indicated in Step 3. The reference voltage value for the black and pink wires is 3.3V, black and red - 5V, black and yellow - 12V.
The specified values \u200b\u200bare allowed to deviate by ± 5%. So the voltage is:
3.3V should be within 3.14 - 3.47V;
5V should be within 4.75 - 5.25V;
12V should be between 11.4 - 12.6V.
Visual inspection of the power supply
Step 1. Turn off computer. It must be remembered that the power supply unit of the computer operates with a voltage dangerous to humans - 220V.
Step 2. Open the side cover of the system unit.
Remember, or for convenience, take a picture of how the power is connected to each of the components (motherboard, hard drives, optical drive, etc.) and then they should be disconnected from the power supply.
- 1. Causes and symptoms of power supply failure
- 2. Checking the voltage supply by the power supply
- 3. Checking the correct operation of the PSU
- 4. Visual inspection of the power supply
If, after pressing the power button, your computer shows no signs of life, then the problem is most likely in the power supply. But do not rush to go to the store for a new device, first it would be nice to make sure that the existing device is really faulty.
This article is devoted to the question of how to check the computer's power supply yourself using available tools. We hope it will save our readers time and money, as well as broaden their horizons and give an incentive to a more detailed acquaintance with the insides of the PC.
Causes and symptoms of power supply failure
Power supply unit (PSU) is a device that converts alternating voltage into direct voltage and provides power to various computer nodes. This device acts as a connecting element between the electrical network and the components of the PC, and therefore in the event of a power supply malfunction, your entire home platform fails. The reasons for the malfunction can be as follows:
- Voltage drops in the network and its out of the operating range of the power supply. This is an extremely common problem in our country, and therefore we recommend that you additionally purchase an uninterruptible power supply unit, which, in the event of a voltage drop or surge, will save your components from premature death;
- The low quality of the PSU itself, which is typical of cheap copies. Many consider the power supply to be a secondary element, which is partly true, and therefore choose it on a leftover basis, but remember that without this node your computer cannot function, and if its quality is low, more expensive elements like a video card or a motherboard are at risk.
If you do not know what exactly caused the computer malfunction, then the following symptoms speak in favor of problems with the power supply:
- Pressing the power button does not lead to any consequences - there is no light indication or sound, the fans located inside the case do not start rotating;
- Also, the computer may not turn on every time. The reason for this behavior may be problems not related to the power supply, for example, a sunken power button, but it is still worth being wary when a similar situation repeats;
- The PC can turn on, but after a few seconds it turns off without waiting for the operating system to load. This behavior is also typical of a computer when it overheats;
- Excessively high temperature of the system unit. Again, this may also speak in favor of overheating, but both of these problems are very dangerous for the integrity and performance of the computer.
There are several ways to check the operability of this device, they boil down to checking the voltage, its range, and also a visual inspection of the unit. Let's talk about each of them in a little more detail and give step-by-step instructions for their implementation, so that you can independently check the status of the power supply unit.
Checking the power supply from the power supply
Remember that despite the fact that the computer does not show signs of life, the first step is to disconnect it from the mains, since the power supply operates with a voltage of 220 volts, which is dangerous for humans.
Even if the fan starts working, this does not guarantee the serviceability of the power supply, but it at least turns on. To check the full functionality, you need to conduct the following test.
Checking the correct operation of the PSU
We remind you that the computer must be turned off! Further:
Visual inspection of the power supply
After turning off the power supply to the PC and disconnecting the power supply unit as in the previous methods, we now need to unscrew it, as a rule, it is seated on four screws. Following this, we disassemble the power supply itself, unscrewing 4 screws on its case, connecting the two covers of the power supply unit.
Now it is important to carefully inspect the unit, there should be no swollen capacitors on it, the fan should have free space for movement, and if dust has accumulated in the power supply unit, it must be removed with a vacuum cleaner. If the capacitors are still out of order, you can rewire them yourself to new ones with the same rating, and you can try to lubricate the fan or replace it in case of failure. Remember that if you had no previous experience with a soldering iron or using thermal paste, then your attempts to fix the power supply may be more damaging for it than the primary reasons for inoperability.
If none of these methods gave the desired result, then, most likely, the unit failed with both ends. But if you are the happy owner of a power supply unit of enormous power, and, accordingly, cost, then you should still contact a service center and ask for its repair, and subsequently take care of the safety of your device from voltage surges in the network. Increased caution can always save you a lot of money, keep this in mind.
Hello dear readers! Today we will deal with a purely practical matter. If you are interested in the "hardware" of the computer, then it is good to consolidate theoretical knowledge with practice, right?
Let's say you bought a new one for your computer. Or you want to replace the burned-out block with another, used one.
You can install it right away (and play the lottery), but it's better to check before installing. You want to know how to do this, right?
Standby voltage source
First, a little theory. Where without her!
Computer contains standby voltage source(+5 VSB).
If the power supply plug is plugged into the mains, this voltage will be present at pin 21 of the main connector (if the connector is 24-pin).
This standby power supply starts the main inverter. A purple (most often) wire comes to this contact.
It is necessary to measure this voltage against the common wire (usually black) with a digital multimeter.
It should be within + 5 + -5%, that is, be in the range 4.75 to 5.25 V.
If it is less, the computer may not turn on (or will turn on "once"). If it is larger, the computer may freeze.
If this voltage is absent, the power supply unit will not start!
Lightweight power supply loading
If the standby voltage is normal, it is necessary to connect the load to one of the connectors in the form of powerful resistors(see photo).
A resistor of 1 - 2 Ohm can be connected to the +5 V bus, and 3-4 Ohms to the +12 V bus.
The power of the resistors must be at least 25 W.
This is far from the full value of the load. In addition, the + 3.3V bus remains generally unloaded.
But this is a necessary minimum, at which the power supply unit (if it is in good working order) should start without "harm to its health".
The resistors should be soldered to the mating connector, which can be taken, for example, from a faulty external case fan.
Power supply startup
After the load is connected, close the PS-ON contact (most often green) with the adjacent common (usually black) conductor.
The PS-ON contact is the fourth from the left in the top row if the key is on top.
You can close it with a paper clip. The power supply should start up. The blades of the cooling fan will start rotating.
We remind you that it is better not to turn on the computer power supply without load!
First, it has protection and control circuits that may prevent the main inverter from starting. Secondly, these chains may be completely absent in "lightweight" blocks. In the worst case, a cheap power supply unit can fail. Therefore, do not buy cheap power supplies!
Output voltage monitoring
Output voltages will appear on all connectors. All output voltages should be measured. They should be within the 5% tolerance:voltage + 5 V must be within + 4.75 - 5.25 V,
voltage +12 V - within 11.4 - 12.6 V,
voltage +3.3 V - within 3.14 - 3.47 V
The voltage value in the + 3.3 V channel may be higher than + 3.47 V. This is due to the fact that this channel remains without load.
But, if the other voltages are within the normal range, then with a high degree of probability we can expect that the voltage in the + 3.3 V channel under load will also be within the normal range.
Note that the 5% upside tolerance for + 12V is too big.
This voltage powers the spindles of the hard drives. At a voltage of + 12.6 V (the upper limit of the permissible range), the driver microcircuit controlling the spindle overheats and may fail. Therefore, it is desirable that this voltage be less - 12.2 - 12.3 V (naturally, under load).
It should be said that there may be cases when the unit works at this load, but on the real one (which is much larger), the voltages "sag".
But this happens relatively rarely, it is caused by hidden faults. You can make, so to speak, an "honest" load that simulates a real mode of operation.
But it's not that easy! Modern power supply units can deliver a power of 400 - 600 W or more. To test operation with variable load, it will be necessary to switch powerful resistors.
Powerful switching elements are required. All this will warm up ...
A preliminary conclusion about performance can be made even under light load, and this conclusion will be reliable in more than 90% of cases.
A few words about fans
If a used one makes a lot of noise, it most likely needs lubrication. Or, if it is badly worn out, replace it.
Most of all, this concerns small fans with a diameter of 80 mm, which are installed on the rear wall of the power supply.
The fan with a diameter of 120-140 mm rotates at a lower speed to ensure the required air flow, so it makes less noise.
In conclusion, we note that a high-quality power supply unit has a "smart" control circuit that controls the fan speed depending on temperature or load. If the temperature of the radiators with power elements (or the load) is low, the fan rotates at minimum speed.
As the temperature rises or the load current increases, the fan speed increases. This reduces noise.
Victor Geronda was with you.
