Power contacts on the computer power supply. How to turn on the power supply without a motherboard PC power supply turn on and close

The skill of starting a power supply without a computer and motherboard can be useful not only to system administrators, but also to ordinary users. When problems arise with your PC, it is important to check the functionality of its individual parts. Any person can cope with this task. How to turn on the power supply?

How to turn on the power supply without a computer (without a motherboard)

Previously, there were power supplies (abbreviated as PSU) of the AT standard, which were launched directly. With modern ATX devices, such a trick will not work. To do this, you will need a small wire or a regular paper clip to close the contacts on the plug.

On the left is a 24-pin plug, on the right is an older 20-pin plug

Modern computers use the ATX standard. There are two types of connectors for it. The first, older one, has 20 contacts on the plug, the second - 24. To start the power supply, you need to know which contacts to close. Most often this is the green PS_ON pin and the black ground pin.

Note! In some “Chinese” versions of the power supply, the wire colors are mixed up, so it is better to familiarize yourself with the contact diagram (pinout) before starting work.

Step-by-step instruction

So, when you have become familiar with the wiring diagram, you can start starting.

It happens that it becomes necessary to turn on the PSU (power supply) of the computer without the participation of the computer itself, or more precisely, without connecting to the motherboard.

Basically, this need arises when, for example, it is necessary to check the health of the power supply or in order to power some device with a voltage of 5 V or 12 V.

I once had to use an ATX power supply as a power supply for my D-Link modem.

You can also use the ATX unit as a power supply for an old radio and for much more.

Turning on the power supply without load

I will describe two options.

First way

In order to start the ATX unit, you simply need to short-circuit the green and any black wires on the power supply connector (PS-ON and GND pins, respectively, see the figure below).

This is what it looks like in real life:

It also happens that on some power supplies these wires may be of different colors (you understand - the Chinese), so I recommend taking a closer look at which wire you have as the PS-ON output.

Second way

If you don’t have a piece of wiring at hand, then the same steps can be done using a regular paper clip. We close all the same colors of wires.

Read also:

Why can't you turn on a computer power supply without a load?

Now a few precautions.

If you don't do this, the voltage conversion circuit may fail and require expensive repairs. ATX power supply repair, and maybe its complete replacement due to the economic irrationality of repairs.

By the way, it happens that some power supplies simply may not start without load.

There are times in life when it is necessary turn on the power supply without connecting it to the motherboard. There are several reasons for this inclusion. For example, check the functionality of the power supply or find out the noise level of its cooler.

Now all power supplies are of the ATX standard. Such units have several “pigtails” with SATA and Molex connectors for connecting drives, several connectors for supplying power to the video card, 4-pin or 8-pin power supply to the processor, as well as 24-pin (possibly 20-pin) power supply to the motherboard.

In addition, there is a latch key on the connector for connecting to the motherboard. So next to it there is a black wire with a hexagonal contact. If you turn the cable with the locking key down and count the fifth contact from right to left (can be labeled COM or GND), then this will be exactly it. Near this COM pin there is a green wire, in the same row. This is the only wire and can be called on the cable as PS-ON. If in doubt, turn the cable again with the locking key down and count the fourth contact from right to left.

This method of finding the desired contact is universal and does not depend on the number of contacts on the cable. Whether it's 24-pin or 20-pin. By the way, there are power cables with detachable 4-pin connectors. They are also labeled 20+4-pin.

It may be that you have a Chinese power supply from an unknown manufacturer and the green wire is missing. Don't worry. The order of the wires does not change from this.

Now you need to take a small piece of wire or paperclip, expose its edges. One end is connected to the fourth pin contact, and the other to the fifth pin contact. Although you can connect another contact to any of those that have a black wire. For example, to the third pin contact.

Now you can turn on the power supply by connecting it to the network. The power supply will work immediately. You will know this by the rotation of its cooler. If the power supply has a controlled cooling system, in which the cooler does not rotate at low loads, then try connecting a cooler from the system unit or an optical drive. This will also help ensure that the power supply is in working order.

How to turn on a computer power supply without a computer?

It can work in this mode for no more than 5 minutes. After all, this mode of operation, without load, should be short. So before connecting to the network, still connect either a cooler or a disk drive, or a hard drive. Check what worries you and turn it off. Read more interesting tips in the section

Lately, I have often encountered problems with the PC power button - Power buttons. Previously, I did not give it much importance and did not pay due attention. But in vain!

It happens that there is power in the network, the power supply, when the corresponding contacts of the connector are closed, starts with half a turn and works great. The motherboard signals with its LED the presence of standby voltage, but when pressed pwr buttons Nothing happens. The computer won't turn on!

Of course, there can be a great many reasons for this behavior, but it’s still worth paying attention to the PC power button!

What to do if the computer does not turn on?

1. You need to check the functionality of the power supply.

2. Start the PC, bypassing the power button, which is located in the PC case.

How to check a computer's power supply?

I answer. Express check of a computer power supply is carried out as follows:

1. Disconnect all power supply connectors from the computer (from the motherboard, from the video card, from all kinds of hard drives, coolers, and so on).

2. Now you need to short-circuit the two wires on the next connector. It is the widest of all that come out of the BP. You can short any black wire to a green wire. As a rule, I I close green and middle black(Earth). This can be done with a regular paper clip or tweezers.

If the power supply is supplied with 220 volts from the outlet, the wires are connected correctly, the power button on the power supply itself (there are such models) is turned on, and the fans of the power supply do not start, then we can state that the power supply is faulty. On the contrary, if, when you close the indicated contacts on the computer power supply connector, you see that the fans inside the unit are rotating, and not just twitching or silent, then the power supply is working.

At the same time we learned run a computer power supply without a computer!

Many experienced technicians may argue that such a test cannot accurately show the serviceability or malfunction of the power supply. And they will be partially right. But we do an express check, which in this case is quite sufficient. Moreover, not every user has a load stand or at least a multimeter to go deeper.

After checking the power supply, connect all connectors back. And we solve the next problem.

How to start a computer without a button?

Each motherboard manufacturer may have a different pin layout. Therefore, the best search option would be to open the documentation for your motherboard and find the location of these pins there. The documentation for the motherboard must come from the store; if you lost it or the seller did not give it to you (which happens very rarely), then the documentation for the motherboard can be downloaded online from the manufacturer’s official website if you have access to the Internet!

If there is neither one nor the other, then we look for the inscriptions on the connectors. As a rule, they are signed with letters Power Switch (PW Switch), Power ON, On-Off, not to be confused with PWRLED.

Here are typical connector pinouts from some manufacturers:

MSI motherboard

Asrock motherboard

Asus motherboard

Biostar motherboard

Epox motherboard

Gigabyte motherboard

Foxconn motherboard

Intel motherboard

We remove our connectors and carefully Briefly close the contact PWR SW and Ground. The computer should start. What to close? Ballpoint pen!

If the computer starts up, then the conclusion is obvious: the power button is faulty. What to do in this case? Try reconnecting the button to the motherboard connector; there may be a bad connection. If this does not help, remove the button, and then, depending on the circumstances, either repair the button or replace it.

To get out of this situation for a while, you can connect instead of the power button reset button(reboot) and use it to turn it on.

Thanks to these simple steps, you can start the computer without any problems, but this should not be neglected, and it is better to quickly repair the start button on the case to avoid unnecessary problems.

Attention: Neither the author of this article nor the administration of this site bears any responsibility for possible problems that may arise when turning on the computer in this way. You will perform all of the above actions at your own peril and risk, and will be solely responsible for possible problems that are not described in this article.

Therefore, if you do not have sufficient qualifications and knowledge, I recommend that you contact a specialist.

The need to supply power to the adapter for connecting an external hard drive via a USB socket to a personal computer made me remember the JNC LC-200A power supply that had long been collecting dust on the mezzanine. Voltage of 12 and 5 volts is available, there is plenty of current. What can I say - a profile power supply in such situations is always the best option.

He performed his function successfully. I decided not to look for another power source for these purposes, but the abundance of wires coming out of it confuses me. And there is only one way out, since I decided to use it constantly - it needs some modification.

I disassembled the power supply into separate units, painted the case, drilled holes in the lower part for the terminals and installed rubber feet on the bottom (which I installed first, otherwise by the time you assemble it, you will strip off the entire table with the iron bottom).

I installed terminals for all types of available voltages, let them be. Red ones are “+12”, “+5”, “+3.3” volts, and black ones are “0”, “-12”, “-5”. Moreover, using their different combinations, you can obtain a very wide range of constant output voltages.

Took it for a fee. The wires going to the fan were previously simply soldered - I installed a connector in case it was necessary to disassemble the power supply in the future.

Of the output wires, I left two harnesses untouched, shortened and combined the rest (in accordance with the color and, of course, the output voltage).

The board was in place, the shortened wires to the terminals, and the whole bundles were brought out.

I screwed the upper part of the case into place, left a power connector for connecting hard drives with an IDE interface on one output harness, and installed a connector for drives with a SATA interface on the other. I signed the power terminals in the simplest and most accessible way - I printed out the necessary symbols, pasted tape on top of the text, cut it out and pasted it.

Reverse side of the assembled power supply. The power button is located in a convenient niche; turning it on or off accidentally is almost impossible. And this is not a trifle, since if the power from an external hard drive connected to the computer is unauthorizedly disconnected, adverse consequences are possible. Using the modified power supply to connect the HDD is incomparably more convenient, I would even say comfortable. Plus, the ability to use the power supply to obtain other very different constant voltages.

Getting different voltages - connection table

Also, the power supply has become more compact and mobile, so there will be a lot of applications for it - the need for a powerful and separate source of various voltages arises often. Author of the project - Babay iz Barnaula.