new PSU not turning on

New PSU Not Turning On: 4 Reasons Explained with Solution

So, you just bought a new PSU to get your PC going. Exhilarated, you set it up and try switching your PC on. But looks like the new PSU is not responding whatsoever. 

And just like that, all your enthusiasm has been washed down the drain. What makes it worse is that you don’t have a single clue about what went wrong.

What are the reasons for the new PSU not turning on?

Loosely plugged cables are one of the most common reasons for PSU not turning on. If plugging them properly doesn’t help, your 24-pin connector might be loosely joined. Excess heating and Low voltage of electricity supply can also result in your PSU not turning on.

This is just an overview. We prepared a much more detailed guide elaborating the reasons including their troubleshooting methods. So, keep on reading.

New PSU Not Turning on (Problem Identified)

Before choosing a new PSU for a PC, one needs to be aware of the computer’s basic requirements. In most cases, people rush to buy PC components without considering the specifications of their PC. 

This leads to various compatibility issues, rendering your PC components unresponsive.

The same goes for your PSU as well.  Your new PSU should get along with your motherboard, processor, and video card. PSU won’t work with the motherboard if the motherboard is not compatible with the PSU.


If all the necessary requirements are not met,  eventually, your PC will not turn on after getting new PSU.

All this might lead you to question:

Why won’t my PSU turn on?

This whole scenario happens because your PSU isn’t compatible with other  PC components. There might be some connection issues with the power source that can keep your PSU from powering up.

Overall, there are a lot of reasons why your PSU might not be turning on. But we’ve narrowed down 4 common reasons that are usually responsible for this problem. We also came up with their troubleshoots to help you fix the problem by yourself.

Let’s jump into the problems and their solutions:

4 Possible Reasons And Solutions 

It’s frustrating when a new PSU doesn’t boot. Well, you may have pressed the on and off button several times by now. It’s more likely your attempts have been in vain and that’s why you’re here. 

Guess we shouldn’t waste any more time and jump right into it:

Reason 1: Loosely Plugged Cables

Power cord is the main PSU cable that supplies power to the PC. It starts transferring its power to the computer’s motherboard once switched on. Sometimes a fully turned-on switch is not enough. You need to check whether the PSU power cord is plugged or not.

The C2G power cable can be a great product for you in this scenario. It’s the best-selling power cord with a stable hold, reducing the chance of loosening up.

Other than that your power strip can be at fault. You can connect your PSU cable to the wrong strip. That could be the reason why the new PSU is not turning on. 

If that’s your issue, look out for the solution we’ve given next:


The first thing we should do is to check on the power supply switch. If the switch is set to on, we move on to check the power cord. The power cord is the main cable next to the switch. Make sure the cable is not plugged loosely.

After getting a green signal from the power cord, check on the power strip. Make sure your power strip and outlets are working. You can plug in another device to see if it works.

Besides, check all the other plugged PSU cables. Check Only those cables that have a direct connection to the computer hardware component.

Reason 2: Unplugged 24 Pin Power Connector

We’ve given you a simple solution to a simple problem in the previous step. But it’s not always that simple. You may need to open up the PC panels to check on some of the major cables.

Don’t worry! We’re not suggesting you do anything extreme with your cables. Here. we’re addressing a minor issue that is easily fixable at home.

As we already know, PSU provides power to the motherboard. And there are three major power connectors to do so. One of them is the 24-pin power connector.

There might be instances where your 24-pin power connector can get loosened up. It might be the reason for your PSU not working when connected to motherboard.

If your power connector is unplugged or loosely plugged your PSU won’t work. You can easily fix this at home. We’re just saving your trip to the computer tech store.

Follow our solution to plug the 24-pin power connector properly.


You can locate this on the upper-right edge of your motherboard. You just need to ensure it’s properly connected to its port. There should be no gaps between the plastic of the connector and the port.

Also, make sure that your Motherboard is fully compatible with the wattage of your PSU. For example, an Asus Prime B450-A should be powered up with at least 450 watts of PSU.


Reason 3: Underpowered PSU

Your new PSU might be underpowered compared to your computer’s voltage requirement. In this case, your PSU can deny starting. It might also restart automatically and frequently.

This not only harms your PSU but also your computer. Your computer will start acting up every now and then. That’ll just add to your misery.

Since you’ve already bought one, upgrade it immediately. But, It’s better to buy a PSU after checking the voltage requirement. 

Corsair is the leading brand when it comes to manufacturing top-quality power supply units for PC. Their RMX series of PSU has been a massive hit and gained a huge following. The Corsair RM750 is a low-noise, modular-powered PSU you can pick. 

With it, you won’t have to worry about your PC’s low voltage issues. Also, there are ways to find out the correct voltage for PSU. 

Find out below!


A multimeter is your savior here. This tool gauges voltage, currents, and resistance. You can take help from any tech store to check your computer’s voltage. If you are already into tech, you might have one at home.

Picking the right multimeter is a tricky task. Especially as you have to consider multiple variables to choose to get an accurate reading of your PC’s voltage. Luckily, we have some recommendations just for you!

We handpicked 3 particular multimeters that were able to give a detailed and accurate reading of the voltage. They are versatile in calculating multiple metrics and have overall satisfactory output. Check them out! 

Product FeaturesPrice
AstroAI 2000 Counts Digital Multimeter 2x/second sampling speedSupport Data hold and Continuity BuzzerOverload protectionBuy Now
KAIWEETS Digital Multimeter Lifetime aftersale service and technical supportAnti-burn safety, certifiedBacklight functionBuy Now
Fluke 117 Digital MultimeterLow input impedance400 hours battery lifeNon-contact voltage detectionBuy Now

What separates these multimeters from other similar products is their impressive accuracy. These multimeters can handle overload better and emphasize the safety of the users. Use them to measure your PC’s voltage intake.

Once you know the requirements go to the shop to search for your desired PSU. Remember, it’s not always advisable to buy the exact same volts size. You can go bigger. But not too big to lead to a blow-up.

Reason 4: Excess Heating

Overheating of your new PSU can also cause why it’s not turning on. This normally happens due to fan failure. You may notice that your PSU works but computer won’t turn on, leading your PSU to fail.

Now, you might wonder:

What happens when a PSU fails?

Well, a malfunctioning PSU can build up immense heat, combusting the inner components. It’ll damage the integrated fans and render the PSU unsafe for any further use.

While a new fan shouldn’t have such problems, too much heating up can ruin it. Also if it doesn’t have a heat protector. In this scenario, there’s nothing much you can do except using your warranty.


There’s still hope to spin the failed fan again. You can dust off the dirt from the fan. Dust can stop the fan from spinning. Also, cables can get wired up in the fan. Then you need to untangle the wires.

So, these might be one of your solutions to the problem, why won’t my new PSU work? Now, hopefully solving the issue won’t be as difficult as fixing GPUs failing to downclocking.

Besides, you need to protect your new PSU from future disruptions. Check out how to do that in three simple ways.

3 Things You Can Do to Protect Your New PSU

Managing any electronic device is a tough task. You need to be conscious while dealing with one.

If you’ve resolved the issue, it’s time to prepare it for a bigger battle. A new PSU if maintained properly from the beginning would cause fewer issues.

Here, you can do three things to protect your new PSU. Because a healthy PSU ensures the computer’s good health.

Purchase High-Quality PSU

Buying a PSU is cheaper than repairing it. While buying, you must focus on the build quality. High-quality PSUs vanish all the possibilities of power down. 

So, if your PSU doesn’t promise high-quality output, replace it immediately. It’ll ensure your PSUs longevity and provide a lossless, consistent power supply to your PC. Also, maintain its efficiency level.

We have already mentioned Corsair PSUs. But you can also choose from the vast range of Thermaltake PSUs and MSI PSUs if you want.

You can sleep well without worrying about the power supply unit’s explosion. 

Install Power Protector

A power surge protection is a must for avoiding uncertain power spikes. You should install a power protector between outlets and your PC. 

This will save your PSU from wearing out fast.

Identify Compatible PSU

Compatible PSUs are another major criteria to consider before buying. We’ve already mentioned it in the former parts.

Let’s do a quick recap!

An underpowered or overpowered PSU can damage your PC to the extent of power off. You might need to buy a new PC as well as a PSU.

It’ll definitely cost you a fortune.

For that, you should do your research beforehand. 

So, we’ve come to the end. We tried to help you with all the possible reasoning. Go through the solutions again to clear out all the confusion.

It’s not rocket science. You can do it!


Why There’s No Display After Installing a New PSU?

RAM can be an issue if there’s no display after installing a new PSU. But first, check on your CPU fan. If it’s spinning, then open the panels to remove RAM. After removing RAM from its slot, clean it and place it back. Check all the CPU cables and GPU. 

What to Do After Installing a New PSU?

After installing a new PSU you can do a quick check-up on whether all the connected components are working well. Make sure to check on the heating system of your PSU. Overheating may cause serious damage. You can hear the fan spinning noise. If it’s too loud, take it to your technician.

Why Does My Secondary PSU Not Turn On?

Your Secondary PSU may not be turning on because of interchanged PSU cables. Also, it could be the pins in the ATX connector that are not bridged. If your GPU is plugged in, then also it won’t turn on. You can try using a PSU adapter to switch on and off with your PC. 

Final Thought

Hope we cleared up all your doubts regarding your new PSU not turning on. Either using a desktop or laptop you can apply these solutions.

You just need to turn off the power switch while working with cables and make sure there’s no water nearby.

Good luck with your new PSU!

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top