How to check the power supply? Testing and Diagnostics

In a computer system, the power supply is responsible for converting a standard household electric current to a low DC voltage that can be used by the machine during its operation and is responsible for turning on various internal components of the computer.

Typically, common problems with the power supply are a fan that does not rotate when turned on and a completely de-energized computer system. In some cases, frequent reboots of the machine occur due to a faulty power supply that is no longer able to supply direct current to the computer. Such symptoms in the behavior of the technique indicate that an urgent need to check the power supply.

Types of Power Supply Failures

The most common problems with power supplies are:

1. Any power ups, system crashes, or locks.
2. Sudden reboot and intermittent blocking of normal operation.
3. Periodic flash memory check.
4. Stop the fan and hard drive at the same time.
5. Temperature rise and overheating due to fan failure.
6. Small power surges cause a reboot of the entire system.
7. Damage to electrical equipment.
8. The presence of static discharges violates the performance of the system.

Experts believe that IP is a weak link in the functioning of the system.

Particularly dangerous phenomena that indicate a breakdown of the IP:

• the system is completely “dead” (no fan, no cursor);
• smoke;
• bloated switches.

If there is a suspicion of a power problem, the computer’s power supply must be checked.

Power Check Methods

Testing the DC output voltage with a digital multimeter can help identify any potential problems and determine the performance of the power supply.

Security measures:

1. Always use the wires of the multimeter to touch the wires and terminals - never touch parts with your hands.
2. If it is not possible to hold wires or terminals with it, use a stand or clamp to fix it so that you do not hold them by hand.

Necessary materials:

• multimeter;
• Power Supply;
• screwdriver;
• clip;
• a computer;
• grounding bracelet.

First way

Sequence:

1. The very first test to be performed is to check the condition of the electrical outlet. Checking the power supply begins with a visual inspection of it to make sure that it is in good condition and not a source of a problem. Alternatively, connect a desk light to it to make sure that it is in good working condition and that it provides sufficient quality electricity.
2. Turn on the multimeter and set the voltage from 120 to 240 volts depending on the standard mains voltage in the house.
3. Turn off the computer and unplug it. Before opening the housing, make sure that it is properly grounded.
4. Remove the computer cover. Visually inspect the unit and its connectors for any signs of damage or burns.
5. Check computer connectors. They are usually located on the motherboard, hard drive, floppy drive, CD or DVD drive and other auxiliary fans.
6. Look for a power connector that is not in use. If they are not available, simply disconnect any connector you are using.
7. Turn on the multimeter for DC voltage in the range of not more than 12 volts.
8. Plug the computer back into the power outlet, and turn it on.
9. Hold the power connector (not the wires) and locate the black and yellow wires. Insert the black wire of the tester into the hole corresponding to the black wire and the red wire corresponding to the yellow wire.
10. The load to test the power supply is +12 volts. Make sure that the multimeter shows exactly this voltage.
11. While holding the black wire in its current position, move the red wire into the hole corresponding to the red wire of the connector. The reading should be +5 volts on it.
12. If during step 7 and step 8 it shows a different reading or does not show anything, this indicates that the power supply is defective and needs to be replaced immediately.
13. If the readings are correct, then a power off problem may occur due to a malfunction of the computer motherboard.

Second way

Checking the power supply with a multimeter in this way is a general test for the health of the source:

1. Turn off the computer and the switch on the back of the power supply.
2. Unplug the power from the outlet.
3. Open the computer case.
4. Disconnect the power cables from all components inside the chassis.
5. Check each cable from the power source to the component to make sure everything is properly disconnected. Remember how everything was connected in order to assemble it correctly later.
6. You can use a paper clip to check the power source, simulating that it is turned on. To do this, bend the paper clip in the shape of a “U”. This clip will act as pins that are inserted into the power source and give a “Power ON” signal.
7. Find the 20/24 plug connector connected to the motherboard; it is usually the largest.
8. When checking the computer's power supply, close its contacts. Find the black and green pins (15 and 16). Insert a paper clip into the green pin (there should be only one) and the adjacent black pin. Before doing this, double-check that the power is completely disconnected from the electrical outlet and not connected to any components of the computer. The green pin is usually number 15 on the pin chart.
9. Insert a paper clip. Connect the power supply back to the outlet and turn on the switch at the back of the unit.
10. Check the fan. When the power supply receives power, then the rotation of the fan is observed. This makes it clear that it works. If it does not turn on at all, double-check all contacts (after disconnecting) and try again. If it still does not turn on, then most likely the unit is inoperative.

This test will not say what regulatory parameters the unit works with, it will only confirm that voltage is being supplied to it.

Third way

Checking the power supply in this way sets the actual parameters of the IP:

1. Check output through software. If the computer is functioning and the operating system is loading, try using the software to check the power supply output.
2. Check the readings to match the data indicated in the manufacturer's instructions.
3. Turn off the computer, unplug the power from the wall outlet, and then press the power switch on the rear panel.
4. Disconnect all components from the power source.
5. Checking the voltage of the power supply through testing. Connect the test unit to the 20/24 connector. Connect the power supply to the outlet and turn it on, it should automatically work, and the power indicator will light up. Check voltage. The 20/24 connector will have several indicators, but there are 4 basic measurements that you need to look for: +3.3 V DC, +5 V, +12 V, -12 V.
6. Make sure that the voltage is within acceptable limits. If any of the readings is outside the parameters of this range, then the IP is inoperative and needs to be replaced.
7. After it is established that the main connector is correctly supplying power, check each of the other connecting cables.
8. Turn the IP on and off between each measurement.
9. When testing, close the power supply: find the green contact on the 20/24-pin connector. Insert the paper clip into the green pin (pin 15) and into one of the adjacent black contacts.
10. Turn on the IP. Set the multimeter to VBDC. If it is in auto range, set the range to 10 V.
11. Connect the negative probe to the ground (black) pin on the connector, and the positive probe to the first output for verification.
12. Check the voltage: if any of the parameters is outside the permissible range, the power supply is faulty.
13. Repeat the process for each of the peripheral connectors. Refer to the specific pinouts for each connector to find out which ones to check.
14. Assemble a computer. Make sure that all devices are connected correctly and that all connectors on the motherboard are correctly installed.

Once you finish assembling the computer, you can try turning it on. If you continue to experience computer errors or the computer does not start, go to the other steps for troubleshooting system problems.

Reverse sensing power connectors

The following table shows the voltage ranges within the tolerances.

Best computer testing software - 2018

Hardware failures occur from time to time, it is necessary to prevent such events with the help of specialized software. Testing your computer's power supply is an important step when it starts to fail. A faulty source can be at the root of all problems, even those that users don’t expect, such as spontaneous reboots, random locks, and even serious error messages.

AIDA64 Extreme (recommended)

This is an advanced system diagnostic utility that can collect important data about the configuration of the equipment and power supply of the computer. The software allows you to test the capabilities of system memory, FPU and CPU, running complex tests. The setup process is quick and easy. AIDA64 Extreme comes with a user-friendly interface. All data related to computer components is divided into separate categories. This software is intended for more advanced users thanks to an extensive set of sophisticated features.

OCCT 4.5.1.

This program for checking the power supply is a powerful and free (for personal use) means of checking stability. Launching the program immediately shows all the useful information about the PC and GPU, as well as a series of graphs that show how the system temperature, processor voltage, RAM usage and other details change. And if they themselves do not detect any problems, OCCT can run tests to use the processor, GPU or power supply, which again will allow you to learn in detail how the temperature, voltage and other system data can react in an emergency.

OCCT will in many cases stop testing if certain measured values ​​are too large. Latest version 4.5.1. The program is free. Platforms: Windows XP, Windows Vista (32-bit), Windows 7 (32-bit), Windows Vista (64-bit), Windows 7 (64-bit), Windows 8, Windows 10.

Open hardware monitor

This is an effective program that tests the state of IP.

The application provides all the information in a simple tabular manner, which makes it easy to monitor the status of the computer over a long period of time. It is designed for users of different skill levels. This program for checking the computer's power supply monitors the primary sensors of the system for the most common chips and provides the most accurate data on the power source.

Setting up a program is an easy task and it does not require any specific configuration. The program comes with a simple interface, it automatically starts monitoring sensors at startup. All data can be exported to a text document. This tool provides a simple solution for finding problems in real time. In the paid version of HWMonitor Pro on the official site of HWMonitor, additional testing functions are included.

Pc wizard

This is a system analyzer that is very effective in checking power and provides complete data on the weaknesses of the equipment. After starting this program, it will take some time to find all the equipment installed on the computer.

A useful tool for analyzing hardware data, including power source information. This is a rather complicated program, mainly aimed at more advanced users.

The presented review includes the best programs that can analyze and provide accurate information about the system’s power supply and much more. To check the full set of application functions and analyze which ones are best suited for the system user, you can go to the official websites of the programs and download the necessary software.