Many computer enthusiasts have a question: "How to turn on the power supply without a computer?" This need is caused by various reasons, most often we are talking about checking the efficiency of cathode lamps or new coolers.
Why such difficulties?
It is simply necessary to turn on the power supply without a computer if it is being repaired, because if you constantly turn off and turn on the computer, this will negatively affect the components of the PC, due to premature battery failure. In addition, any experiments with the computer may lead to unstable operation of the operating system.
First start
As computer wisdom says, if you could find a PC power supply, how to turn it on is easier to understand. All modern computer units comply with ATX (special international standard). Thus, the 20-pin connector has a contact that is responsible for the active state of any such unit. We are talking about the fourth contact on the left (you need to count from the mounting lock). Most often, the contact we need is green. This wire should be tried to close with the ground (i.e., any black). It is most convenient to use the neighboring, 3rd contact. If everything is done correctly, the power supply will instantly come to life, and the cooler will rustle.
How to turn on the power supply without a computer: details
ATX devices can produce the following voltages: 3.3, 12 and 5 V. In addition, they have good power (from 250 to 350 watts). But the question is: “How to turn on the computer power supply?” Above, we have already, so to speak, outlined the procedure in a nutshell, and now let's try to understand in more detail.
In the old days it was easier
It is curious that old blocks that belong to the AT standard could be launched directly. With the ATX standard, things are much more complicated. However, the solution to a huge problem comes down to a small wiring that needs to be connected in a certain way. We already described how to turn on the power supply without a computer, however, we ask you to disconnect all the wires going to the motherboard, hard drives, drives and other accessories. Better yet, remove the element we need from the system unit and work away from it.
Another important point that should not be overlooked: do not make the power supply idle. You can thus shorten his life. Be sure to give a load. For this purpose, you can connect an old hard drive or fan. As already noted, to start, you will need black and green contacts. However, remember that some manufacturers for unknown reasons refuse to follow the established color coding. In this case, it is advisable to first carefully study the pinout. If your knowledge allows, you can make a special button to turn on the power supply.
Unclear computer power problems: PC stopped turning on
First, check the presence of primary power supply ~ 220V at the input of the power supply. Among the reasons for the absence can be called a malfunction of the power filter, sockets, plugs, cable break. Also, the problem may lie in the
uninterruptible power supply. On the back side of many units is a power switch - it may also be faulty or turned off.
In case of primary power supply, even if the computer is turned off, there is + 5V voltage at the PSU output (if everything is working properly). This can be checked by testing the contacts of the PSU connector with a tester. We are interested in pin 9, which has a purple wire (+ 5VSB).
Often, the motherboard has a standby voltage LED. If it is active, there is both a standby and primary nutrition.
If the computer still does not turn on, look for other sources of the problem. The most common causes we will consider below.
1. Open circuit in the power button. To check this, use tweezers to close the contacts responsible for turning on the power on your motherboard, or start the PSU outside the system unit (we described in detail above how to turn on the power supply without a computer).
2. Short circuit that occurs at the output of the power supply. Try disconnecting all devices from power, and remove all adapters temporarily from the slots. In addition, disconnect all USB devices. You can also deactivate the 4-8-pin power connector for the Power Connector + 12V processor.
3. Faulty motherboard or PSU. If only the motherboard is connected to the power supply unit, but it does not turn on, the unit itself is probably faulty. As for the malfunction of the motherboard, which leads to the inability to turn on the power of the computer, we note that theoretically this is possible, but in practice it is extremely rare. To check this, turn on the power supply without connecting the connector to your motherboard. If the PSU turns on, it is the motherboard that is faulty.