Power Supply Won't Turn on When Connected to Motherboard

There are many situations where any user wants to build their PC. However, the power supply may not turn on when the connection to the motherboard has already been made. That means the presence of one or different problems that we consider below.

Of course, there are different drawbacks to be considered to find the solution to each of them. So, here are some of the most common problems, some of the most obvious reasons, and the solutions that a user can implement to use their PC.

Power Supply Won’t Turn on When Connected to Motherboard – Complete Guide

Checking the operation of a power supply is the first step in detecting why a PC won’t turn on. Analyzing the operation of a power supply will save a lot of time finding the most appropriate solution to this type of problem.

Of course, the power supply is one of the most critical components. That is why a malfunction of this component can generate a wide variety of temporary or permanent computer problems.

Even many PC hardware experts check the condition and operation of the power supply when it comes to a PC with problems.

Some of the most common situations that may be encountered are as follows.

  1. The PC does not turn on at all and not at all.
  2. The boot process occurs with different system failures
  3. In the use of the PC, crashes or spontaneous restarts may occur
  4. The hard disk or case fans may not spin up or down
  5. A faulty heat sink and fan may cause the system to overheat, damaging the power supply.
  6. The system memory has several different errors.
  7. Recurrently the user encounters the typical blue screen.

What to Do if the PC Does Not Turn on at All?

This is one of the most common problems when the power supply has a problem or damage. To solve this problem, it is essential to disconnect all the peripherals of the PC that are not important for its operation. Therefore, the user should leave only the monitor, keyboard, and mouse connected in most cases.

Before starting with the proper power supply solution, the external power switch should be checked. Most PC power supplies usually incorporate an external switch located on the back of a PC case. This external switch could be accidentally turned off, which avoids the need to repair the power supply.

Once the external switch has been checked, the computer must be turned on. To do this, the power cord of the power supply must be plugged into a wall socket. A surge protector can also be used when it is suspected that the power supply may be malfunctioning.

There are many models of power supplies that incorporate some notable and valuable features. One of the valuable aspects of the power supply may be the built-in light. This light is often helpful in checking that the unit is on. When this light does not turn on, it is recommended that another plug and power cord be used. This will allow the plug and power cord to be ruled out as the cause of the problem.

When the user detects that the power supply is functioning correctly, he can pay attention to certain aspects of the overall operation of a PC.

Some of the components to pay attention to in these situations are as follows:

  • The mechanical hard drive and case fans should start running. This can be checked by the sound these components make when running.
  • The connection cable between the power supply and the different hardware components of the PC should also be checked.
  • If the power supply is connected correctly and not defective, the motherboard should not have flashing lights. When the motherboard has flashing lights, this is a clear sign of a power supply malfunction.

It is also possible to occasionally find a motherboard that incorporates different light colors. This is an indication of the good or bad performance of the other components. Each manufacturer incorporates a set of colors for different situations. To understand the meaning of each color, you should consult each manufacturer’s motherboard user manual.

Read More: How to Remove CPU Cooler Backplate?

How to Check the Performance of a Power Supply?

Some expert users recommend the use of the jumper test or the paper clip test. This is a simple technique that will allow checking the proper functioning of a power supply. This is performed when this component has been disconnected from other components within a computer.

This technique allows the following problems to be identified:

  • Presence of short circuits in the power supply.
  • Presence of one or more damaged components
  • Some live power connection

The power switch on the power supply should be in the off position and on the back. The paper clip should be bent once the 24-pin connector has been located. This paper clip is inserted into the green pin and the black pins on the other end.

The power supply must be turned on from the switch to verify fan operation. This technique is somewhat simple but lets you know if the user needs a new power supply.

However, it is not possible to detect other problems such as:

  • Voltage fluctuations
  • Overheating
  • Power rail damage and failures

Some users also recommend the use of a multimeter. This is an electronic tool that allows you to measure electrical current from different aspects, such as resistance (ohms), current (amps), or voltage (volts). Although some knowledge is required to use this tool, it is an easy method to check the power supply condition.


Problems in the power supply can be more than enough to generate a great variety of problems in the whole PC. That is why it is essential to verify that this component is in excellent working condition. Even replacing this component can be less expensive than the budget needed for all the repairs of the damage it may cause. Join FinestDesktop for more guides.

Saqib Ali

Saqib Ali, A passionate blogger and Computer Geek help people to build their dream PC. He spends hours in research to pick the right products and then test them and suggest people in guides on Finest Desktop.