DIY step-by-step repair of a computer power supply

Self-repairing a computer power supply is a rather complicated matter. Having taken up this, you should clearly understand which of the components needs repair. Also, it should be understood that if the device is under warranty, then after any intervention, the warranty card will immediately expire.

If the user has little skills in working with an electrical appliance and is sure that he will not make mistakes, then you can safely take on such work. Remember to be careful when working with an electrical appliance.

The power supply is the most important and required component of any system unit. He is responsible for the formation of voltage, which allows you to provide power for all PC units. Also, its important function is to eliminate current leakage and parasitic currents when pairing devices.

To create a galvanic isolation, a transformer with a large amount of winding is required. Based on this, a computer requires a very large power and it is natural that such a transformer for a PC should be large and heavy.

But due to the frequency of the current that is required to create the magnetic field, much fewer turns are required on the transformer. Thanks to this, when using the converter, small and light power supplies are created.

Power Supply - at first glance, a rather complicated device, but if a not particularly serious breakdown occurs, then it is quite possible to repair it yourself.

Below is a typical power supply circuit. As you can see, there is nothing complicated, the main thing is to do everything one by one so that there is no confusion:

In order to start self-repairing a power supply unit, you should have the necessary tools at hand.

First, you need to arm yourself with devices for computer diagnostics:

• working power supply unit;
• post card;
• memory bar in working order;
• compatible type of video card;
• CPU;
• multimeter;

For the very same repair, you will need more:

• soldering iron and everything for soldering;
• screwdrivers;
• the computer is in working order;
• oscilloscope;
• tweezers;
• insulating tape;
• pliers;
• knife;

Naturally, this is not so much for a perfect repair, but this is enough for home repairs.

So, armed with all the necessary tools, you can start repairing:

1. Primarily, you need to disconnect the system unit from the network and let it cool down a little.
2. All 4 screws are unscrewed one by one, that secure the back of the computer.
3. The same operation is carried out for the lateral surfaces. This work is done carefully so as not to touch the wires of the block. If there are screws that are hidden under the stickers, they also need to be unscrewed.
4. After the case has been removed completely, The PSU will need to be blown out (you can use a vacuum cleaner). You don't need to wipe anything with a damp cloth.
5. The next step there will be careful consideration and finding the cause of the problem.

In some cases, the power supply unit fails due to the microcircuit. Therefore, you should carefully examine its details. Special attention should be paid to the fuse, transistor and capacitor.

Often, the cause of a breakdown of a power supply is swollen capacitors, which break down due to poor performance of the cooler. This whole situation is easily diagnosed at home. It is enough just to carefully examine the top of the capacitor.

swollen capacitors

A convex lid is an indicator of fracture. In ideal condition, the condenser is a flat cylinder with flat walls.

To eliminate this breakdown you will need:

1. Extract broken capacitor.
2. In its place a new serviceable part similar to the broken one is installed.
3. Cooler is removed, its blades are cleaned from dust and other particles.

To avoid exposing your computer to overheating, it should be purged regularly.

In order to check the fuse in another way, it is not necessary to unsolder it, but rather connect the copper core to the contacts. If the power supply unit starts to work, then it is enough just to solder the fuse, perhaps it just moved away from the contacts.

To check the fuse is working, just turn on the power supply. If it burns out a second time, then you need to look for the cause of the breakdown in other details.

The next breakdown option may depend on the varistor. It is used to pass current and equalize it. Signs of its malfunction are traces of carbon deposits or black spots. If such were found, the part must be replaced with a new one.

varistor

It should be noted that checking and replacing diodes is not an easy task. To check them, each diode should be evaporated separately or the entire part at once. They should be replaced with similar parts with the stated voltage.

If, after replacing the transistors, they burn out again, then you should look for the cause in the transformer. By the way, this part is hard enough to find and buy. In such situations, experienced craftsmen recommend buying a new PSU. Fortunately, such a breakdown is rare.

Another reason for the breakdown of the power supply unit may be associated with annular cracks that break the contacts. This can also be detected visually by carefully examining the printed strip. You can eliminate such a defect with a soldering iron, after performing a thorough soldering, but you must be good at soldering. With the slightest mistake, you can break the integrity of the contacts and then you will have to change the entire part as a whole.

ring cracks

If a more complex breakdown is found, then excellent technical training is required. Also, you will have to use complex measuring instruments. But it should be noted that the purchase of such devices will cost more than the entire repair.

You should be aware that the elements that require replacement are sometimes in short supply and not only are they difficult to obtain, they are also expensive. If a complex breakdown occurs and the repair costs exceed the price compared to purchasing a new power supply. In this case, it will be more profitable and more reliable to purchase a new device.