Closing the PC power supply. How to turn on the power supply without a motherboard

There are moments 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 power supply for operability or find out the noise level of its cooler.

Now all power supplies belong to 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 processor power, as well as 24-pin (possibly 20-pin) power motherboard.

In addition, there is a latch key on the connector for connecting to the motherboard. So next to it is a black wire with a hexagonal contact. If you turn the loop down with the locking key and count the fifth contact from the right to the left (it can be signed as COM or GND), then this will be it. There is a green wire near this COM pin, in the same row. This is the only wire and can be called PS-ON on the loop. If in doubt, turn the loop down again with the locking key 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 loop. Whether it's 24-pin or 20-pin. By the way, there are power cables with detachable 4-pins. 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. Do not worry. The order of the wires does not change from this.

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

Now you can turn on the power supply by connecting it to the network. The power supply will work immediately. You will recognize 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 with system unit or 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, such a mode of operation, without load, should be short. So before plugging in, plug in either a cooler or disk drive, or HDD... Check what worries and turn it off. Read more interesting tips in the section

Don't underestimate the importance of your computer's power source. Good block power supply serves as the cornerstone of the stability and reliability of your computer. However, it happens that for some reason the power supply unit needs to be replaced. But don't be afraid. Replacing it is a surprisingly simple process. It is more difficult to choose it correctly.

How to unplug your old power supply

Start by unplugging all power cords that are connected to your computer. If your power supply has a power switch located on the back of your computer, switch it to the down (off) position, and then remove the side of your PC.

You will need to disconnect all cables that go from the power supply to the motherboard.

Note: the main 20 or 24 pin connector is most often secured with a key. Move the key aside before removing the connector to avoid mechanical damage board or connector.

Also, remember to remove the four or eight pin processor power connector located next to the processor socket on the motherboard (not available on all motherboards).

In order not to get confused when connecting, you can take a picture of the power cable routing. This way you can be sure which cable connects to which components.

After disconnecting each cable, remove the PSU from the chassis to avoid tangling it with other cables. This will also make sure that all power cables have been disconnected.

To remove the power supply, remove the screws that hold it in the case. In most cases, there are only four screws, but designs may vary depending on the manufacturer.

Installing a new power supply

Step 1

Make sure the power source has enough power to properly power your computer. The processor and graphics card will use the most power. If there is not enough power, your computer may be slow or not start at all.

Make sure the power supply you buy will fit your form factor. This is usually ATX or mATX.

Flip the computer case onto its side. This ensures best access to the place where the power supply is installed.

Open the computer case. In order to access the power supply, you may need to remove some of the PC components. Most often it is a processor cooler.

Install the power supply into the computer case. Most modern enclosures have a special chassis that greatly simplifies installation. If not, install a new power supply in the same way as the previous one.

Make sure all fans on the PSU are not blocked and that it aligns with all 4 screws on the chassis. If this is not the case, the power supply may not be installed correctly.

Tighten all fixing screws outside and inside the case.

Connect the connectors. Once the computer's power supply is secured, you can begin connecting the power cables to the computer's motherboard.

Note: make sure no component is left out and place the wires so they don't get in the way of the coolers. If you have any unused PSU cables, carefully fold them aside (if you have a cable tie, you can use it).

Connect the 20/24 pin connector to the motherboard. This is the largest connector on the power supply. Most modern motherboards require a 24-pin connector, and older motherboards will only use the first 20 pins. Some power supplies have a removable 4-pin connector to make connecting older motherboards easier.

Connect 12V power to the motherboard. Older motherboards use a 4-pin connector, while newer motherboards use an 8-pin connector. It provides power to the processor and should be clearly marked on the cable or in your power supply documentation.

Connect your video card. Graphics systems mid to high end require one or more 6 and 8 pin connectors. They will be labeled PCI-E.

Close the lid of the system unit. Plug in the power supply and make sure the switch on the back is turned on.

Turn on your computer. If everything is connected and working properly, the fan on the power supply should turn on and your computer should boot normally. If you hear sound signal and nothing happens, it is most likely that something inside is connected incorrectly, or the power supply does not provide enough power for your components.

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

Basically, such a 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.

So I somehow had to use the ATX power supply unit as a power supply for my D-Link modem.

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

Turning on the power supply without load

I will describe two options.

The first way

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

This is how it looks in real life:

It also happens that on some power supplies these wires may turn out to be of different colors (you yourself understand - the Chinese), then I recommend that you take a closer look at which wire you have is the PS-ON terminal.

Second way

If a piece of wiring was not at hand, then the same actions can be done using the usual paper clip... We close all the same colors of the wires.

Read also:

Why can't I turn on the computer power supply without load?

Now a few precautions.

If you do not do this, the voltage conversion circuitry could be damaged and an expensive ATX power supply repair, and maybe his complete replacement due to the economic irrationality of the repair.

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

The need to supply power to the adapter to connect the hard external drive via the USB socket to personal computer made me remember about the JNC LC-200A power supply, which had been gathering dust on the mezzanine for a long time. Voltage of 12 and 5 volts is available, current is abundant. But 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 is embarrassing. And there is only one way out, since I decided to use it all the time - some work is needed.

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 put in the first place, otherwise, while you put it together, you will strip the entire table with iron from the bottom).

I put the terminals for all types of available voltages, let them be. Red "+12", "+5", "+3.3" volts, and black "0", "-12", "-5". Moreover, using their various combinations, you can get a very wide range of constant output voltages.

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

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

I brought the board back into place, the shortened wires to the terminals, and brought out solid bundles.

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

The reverse side of the assembled power supply. The power button is located in a convenient niche, it is almost impossible to accidentally turn it on or off. And this is not a trifle, since in case of unauthorized disconnection of power from the connected to the computer hard external disc may have adverse effects. It is incomparably more convenient to use the modified power supply unit for connecting the ZhVD, I would say even comfortable. Plus to this the possibility of using the power supply and to obtain other very different constant voltages.

Getting different voltages - connection table

We get	We connect
24.0V	12V and -12V
17.0V	12V and -5V
15.3V	3.3V and -12V
10.0V	5V and -5V
8.7V	12V and 3.3V
8.3V	3.3V and -5V
7.0V	12V and 5V
1.7V	5V and 3.3V

Also, the power supply unit 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 often arises. Project author - Babay iz barnaula.

When working with a stationary PC, a situation may arise in which the computer simply refuses to turn on. Pressing the "Power" button does nothing, and what can cause this dysfunction is also unknown. Most often, the suspicion falls on the computer's power supply, in case of failure of which the voltage ceases to flow to the motherboard. How to turn on the power supply without a computer and using the "Power" button on the case? Let's figure it out.

Features of turning on the power supply without a PC

As you know, the computer is turned on using the "Power" button, which, in turn, is connected to the motherboard. To start the power supply without a computer, we need to exclude the motherboard from this scheme using the method that I will describe below.

When performing this operation, remember that:

• It is necessary to turn off the PC and completely disconnect the PSU from the computer;
• It is necessary to connect some kind of load to one of the external connectors of the power supply unit (some old hard drive or CD player will do). Without such a load, various negative consequences are possible, in the form of failure of the power supply unit from starting, its failure, and other unwanted dysfunctions;
• Be extremely careful when performing the following operations. Accidentally closing the wrong contacts can damage the device.

We start the power supply without a computer

To get around the motherboard circuit, we'll need some kind of metal clip or a little wire with stripped ends. Even ordinary technical tweezers may come in handy.

The green contact in the circuit is usually depicted as "PS-ON" ("Power Supply ON" - power supply), and black as "COM" ("Common" - common) or GND ("Ground" - ground);

Connector diagram

• The power supply should turn on, and its cooler should start working.

Some craftsmen connect a full-fledged switch instead of such a wiring.

Other ways to check the power supply

There are also a number alternative ways check the operation of the power supply.

Output voltage measurement

To check the performance of the power supply, we can measure the indicators of its output voltage using a voltmeter. To do this, it is recommended to turn on the power supply as indicated above (if included). And measure the indicators of a number of wires of the black and pink wires of the main 24-pin connector. In the case of black and pink wires, the indicator should be 3.3, black and yellow - 12, and black and red - 5 V. The permissible deviation should not exceed 5% in the lower or upper side.

Checking for swollen capacitors

The second way is to check the filling of your power supply for the presence of swollen capacitors on the board. To do this, you need to disconnect the power supply from the PC, remove the cover from it and visually inspect all available capacitors.

If you notice swollen capacitors, then there is a high probability that they have already exhausted their resource and need to be replaced. It is necessary to remove them from your power supply unit, and replace them with new ones of the same denomination.

Conclusion

To turn on the power supply without a computer, you must use a piece of wire stripped from both ends, which to close the 4 and 5 contacts of the main connector of the power supply unit, as described just above. Usually this method is universal, and makes it possible to understand the overall performance this device... If the unit does not turn on, then it is quite possible that it needs a thorough repair.