The power supply is an integral part of any equipment, including a computer. Faults in the computer's power supply can only be determined physically, that is, visually. There is no software way to do this. Next, possible malfunctions of the computer power supply will be considered.
How is the block
To more accurately detect a malfunction of the computer's power supply, you need to understand its device. Schematically, the block consists of several main nodes.
The first half is galvanically connected to a network containing a filter, a standby power supply circuit, a rectifier and transistor switches of the converter.
This also includes the scheme of the force correction factor.
In the second half, input voltage filters, a control circuit, a stabilizer of a PWM controller chip, a standby voltage stabilizer and a rectifier are enclosed. Working with this part is safer, as it is network independent.
Now there is a general idea of how the computer's power supply is arranged in order to proceed with its diagnosis.
Power Supply Preparation
Before proceeding with the repair of computer power supply failures, you need to prepare it.
To do this, you need to completely remove the cover of the power supply housing and remove the board. After that, it is necessary to discharge the capacitors of the mains voltage with an incandescent lamp. Now you can start the inspection.
Troubleshooting
The first visible sign of a computer power supply malfunction is a bloating capacitor. You can also observe burned out elements that exude an unpleasant burnt odor. This can also be a symptom of a malfunctioning computer power supply.
If the unit has been used for a long time, then its inoperability can be a consequence of the aging of its components. This "affliction" most often affects capacitors filled with electrolyte. Rectifiers and output stages also suffer. When the liquid in the capacitors is in an unstable state, you can see it from above - it will leak, and the capacitor will look swollen.
If used improperly, overheating can occur, that is, it is necessary to clean the power supply from dust in a timely manner.
Incorrect operation of the entire system may indicate a malfunction of the computer’s power supply: random (periodic) reboots and freezes.
Where to begin?
Since it is not possible to find out the model of the power supply programmatically, it is worth referring to the instructions that came with the unit. Unfortunately, it is not always possible to save documentation that was in the package, so you need to open an Internet browser from any other device.
On the power supply unit there is a name for its model, so it must be indicated in the search line along with the query "Possible malfunctions. The computer power supply unit does not start."
Before starting an independent repair, it is worth considering the option of an incorrect energy load. All components in the system unit consume a certain amount of energy, so the power supply should be selected based on the data of all components. For example, the total amount of power consumption is 350 watts, and the power supply is connected with a volume of 300 watts.
In the best case, the computer simply will not start, and in the worst, some parts or the entire system will burn out. To find out the energy consumption of the entire system, you need to use the online calculator, which enters the data of each component, and the calculator selects the optimal amount of power supply. This will help avoid signs of a malfunction in the computer’s power supply.
Power supply pinout
In modern power supplies, the main cable that connects to the motherboard is considered to be 20 + 4 pins. This cable and connector will be needed for further actions.
Each contact has its own unique input voltage. To find out, you need to look at the power scheme of your power supply on the Internet.
The easiest way to check one of the symptoms of a malfunctioning computer power supply is to use a power supply and a paper clip. However, it is not safe both for the block itself and for the one who will check it.
Tester check
Another option for checking the main malfunction of the computer's power supply is to use a tester. To do this, remove the side cover of the system unit to gain access to the motherboard. Next, you will need to disconnect all the unit cables that are connected to the accessories on the motherboard. The only component that is not dangerous for voltage surges is a disk drive. Modular units in this regard are much simpler - their cables are disconnected from anywhere.
After that, you need to use a clip and a loop, which is designed for the motherboard. Contacts on it, which are marked in black and green, need to be bridged with a paper clip. Now you can connect the power supply to the network and use the tester.
The unit is switched on using a special button located on it. Next, you need to look into the tester, and if some indicators deviate from the norm by at least one unit, then this indicates an unstable voltage. This method allows you to figure out how to find the cause of the malfunction of the computer's power supply.
Loud noises
Sometimes the power supply makes an unpleasant noise during startup and operation. How to look for a malfunction in the computer's power supply in this case? The noise that the unit makes is a fan, or rather, its malfunction. The easiest option is to replace the fan, but not all are satisfied with this method.
Fan preparation
So, when all the cables were disconnected from the motherboard, you can proceed to disassemble the power supply. On the side where the fan is, there are four screws that need to be unscrewed - they fix the cover.
A fan is attached to this cover, but we will return to it later. You need to pay attention to the remaining parts of the power supply - if they are dusty, you can use a dry cloth, brush or a mini-vacuum cleaner. Having got rid of dust, you can start lubrication.
The two-pin cable that leads to the fan must be disconnected from the power supply. The power supply board itself is also subject to detachment, which is fixed on the case with screws (they need to be unscrewed). The board will need to be cleaned on both sides.
Fan lubrication
Now we’ll deal directly with the fan. It is better not to touch the blades with your fingers, even to wipe off the dust, since particles stick to the greasy surface faster.
Having cleaned the fan of dust, you need to find a sticker on it and remove it. After that, you need to raise the edge of the rubber stopper with an awl or other thin object, because the stopper cannot be damaged.
Under the cork itself is the impeller axis, and a lock washer in the middle. If the puck is hardly visible, then you can use a dry cotton swab and wipe it. This must be done carefully so that no lint remains on the washer.
There is a transverse section in the lock washer into which a screwdriver is inserted, thereby prying it to pull it out. After this, the last small detail remains - the rubber ring, which is also subject to removal. Now you can remove the impeller. It remains to clean the inside of the entire surface of dust, again, a dry cotton swab will help.
We return to the fan frame with the engine. By lifting a small round plate, you can see the accumulation of dust, which also needs to be disposed of. In the center of the circle is a sleeve that makes noise during operation. The fact is that from time to time it must be lubricated. Ordinary engine oil is ideal for this.
Reverse assembly
So, it is not difficult to assemble the fan back; however, if this was done for the first time, it is difficult to remember the sequence. The first thing to do is to put the engine back in place and place the impeller on it.
After that, a rubber ring is placed in the center, and a lock washer is mounted on top of it, it must be aligned. The fastest way is to place the puck with vertical tweezers.
A couple of drops of oil around the washer will not be superfluous. A rubber stopper is applied on top, on which a sticker is glued.
The fan assembly was successful, you can continue to assemble the power supply by returning the fan to the unit casing. After that, you need to fix the board to the power supply housing and connect the fan to the board. After that, it remains only to fix the cover and connect it to the motherboard. If the noise is not eliminated after lubrication, then the matter is a fan malfunction, which must be completely replaced.
Useful Tips
A power supply is not the most expensive part of a computer, however, work is impossible without it, so you should monitor its condition. The article examined options for how to find faults in the computer's power supply and how to fix them.
Before starting any manipulations with the power supply, it is important to know that inside there are high-voltage power capacitors that need to be discharged. To do this, you just need to disconnect the power supply from the network and let it stand idle for 15-20 minutes. More experienced professionals can self-discharge them. It takes less time, but the risk is great.
To begin with, you should know that even a large number of additional coolers in the case will not protect the power supply from getting into it. It is for this reason that you need to clean it and the entire system unit from dust as often as possible. Untimely care leads to a greater sticking of dust, which entails overheating of the components.
Capacitors are also an urgent problem with a computer power supply malfunction. Their unusual condition can be seen with the naked eye - they are swollen, and in some electrolyte flows outward from above or below. You can fix this failure yourself if you know the thickness of the board and be able to use a soldering iron.
Getting rid of dust in the power supply, it is important to use materials that do not leave hairs or fibers, since they can stick, heat up and leave burned out places. Ideal devices for cleaning are brushes and brushes with soft plastic filler, mini-vacuum cleaners.
It is only necessary to repair the power supply if you have experience handling similar equipment. In any case, you should consult with a computer technician to make sure that the problem really lies in the power supply.