How to Check What PSU You Have Without Opening Your PC Case

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How to Check What PSU You Have Without Opening Your PC Case

Key Points

  • Determining what PSU is in your computer can provide valuable information without the need to open the case, which can be inconvenient and risky.
  • You can check what PSU you have by looking in the manual that came with your computer or by looking up the model number on the manufacturer’s website.
  • If you can’t find the model number, you can search for a label on the power supply itself, typically located on the back of the PC case.
  • Contacting the manufacturer or calculating the power consumption are other options to determine the type of PSU in your computer.
  • Knowing what PSU is in your computer is important for upgrading components and ensuring compatibility, especially for PC gamers and laptop users.

Determining what PSU is in your computer can provide some valuable information. Unfortunately, opening the case is the most common way to verify the power supply. This is inconvenient and risks damaging delicate components when opening the case. A better option is to check your PSU without opening the case.

Details about wattage and connections allow you to upgrade components with peace of mind. However, there is also plenty of other important information about a power supply. For instance, knowing what PSU you have can help to troubleshoot problems. Keep reading to learn what type of PSU is inside your computer.

How to Check What PSU You Have

Before we start, the steps outlined below cover pre-built and custom-built PCs. The two have a few differences, but the basics are the same. Similarly, much of the information also applies to laptop PSUs, but remember that those are outside the computer on the charging cable. Now, let’s get to work!

1. Check Your Manual

The easiest way to check what PSU you have without opening the PC is to look in the manual. The manual that came with your computer has plenty of information, including the power supply unit’s specifications. If this is a pre-built PC, then it may not list the exact specs. However, it should still list the basics, such as the wattage of the PSU.

If you purchased the power supply separately, the manual that came with the unit will spell out all of the technical details, like the types of connections and the voltage of each line. If you are trying to replace a failed PSU, knowing the wattage and output should help you determine how much power you need in your new supply.

Check what PSU you have
The manual that came with your computer includes the power supply’s specifications.


2. Look Up the Model Number

If you don’t have the manual, don’t panic. You can still check what PSU is in the computer without opening the case. To do this, you will need the model number for the computer if it is a pre-built PC or the model number of the PSU for a custom build. The model number on a pre-built computer is on a sticker, typically on the backside of the computer.

Alternatively, you can find the original purchase’s model number on the receipt or order details. Some pre-built PCs from companies like HP and Dell even have PC management software that should list the device’s model number. Then, take the model number and look it up on the manufacturer’s website.

The manufacturer’s website will have all of the original documentation, such as the computer’s specs, and copies of the manual. If you built the computer and have the power supply model number, you can look it up directly on the power-supply manufacturer’s website. This will give you access to detailed information about your PC’s power supply, as well as the original manuals.

Check what PSU you have
You can look up your computer’s model number on the manufacturer’s site to see what PSU you have.


3. Look for a Label

Unfortunately, there won’t be a model number available for custom-built PCs. This is when you need to search for a label directly on the power supply. This method also works for pre-built PCs, but you may have trouble getting details about proprietary power supplies. You need to carefully look around the PC case for a label with information about the power supply.

The most common location for the power supply is on the back of the PC case. To find it quickly, follow the power cable to where it enters the PC. Search the surrounding area until you find a small label. The information on the tag varies between brands, but it should have a model number. With this number, you can look up the owner’s manual to find more detailed information.

Check what PSU you have
The power supply is usually located on the back of the PC case.


4. Contact the Manufacturer

The next option to determine what kind of power supply is in your PC is to contact the manufacturer. This won’t work for everyone because custom builds are usually self-assembled. However, the manufacturer should be able to look up your purchase if you registered the device, or if you can provide the serial number.

Keep in mind that many big-name computer manufacturers use custom power supplies and may not give out specific details on those units. Even if the computer didn’t come from a name-brand manufacturer, there is a good chance that you can still contact the company that built it. Companies that provide custom PC building services typically track the components going into the devices they sell.

Find out what PSU you have
You can contact the company that built your PC or PSU to get more information.


5. Determine Power Consumption

The final and least accurate method to check the type of PSU in your computer without opening the case is to calculate the power consumption. The wattage is the most important factor of a power supply. Wattage dictates how much power the unit is capable of. Therefore, you can add up the power each component uses to determine a minimum wattage.

For instance, the GPU uses the most electricity, so start by looking up how many watts your GPU pulls. Then, go through each component, such as the CPU, hard drives, and fans, to determine the current load. For example, if all of the components add up to 415 watts, then the computer likely has a 500-watt power supply or larger.

Check what PSU you have
Use a wattage calculator to add up the power each PC component uses.


How to Check What PSU Your Laptop Uses

A laptop works a little differently than a desktop because the PSU is typically on the power cable rather than inside the computer itself. The PSU on the power cable takes AC power and converts it to DC, just like a desktop. Many of the steps above, such as looking for a label, do translate over to laptop PSUs. However, there is one vital difference between laptop and desktop PSUs.

A laptop must use the power supply designed for it, whereas a desktop PSU is much more universal. Therefore, it is important to contact the manufacturer if you aren’t sure what PSU your laptop uses. They will help you determine the model number of the PSU and can also help you purchase a replacement. Remember, even if a laptop charger “fits” in a socket, it may not provide the proper voltage and amps.

Why You Should Know What PSU Is in Your Computer

PC gamers can typically rattle off the specs of their gaming rig, but the average computer owner has only a basic understanding of the components in their PC. However, knowing what PSU is in a computer provides some valuable insight. Most importantly, it tells you how much power your PSU produces, which is critical if you plan to upgrade components.

On the other hand, laptop PSUs are even more critical because you must match the power cord to the device. Some newer laptops, like Apple’s M1 MacBook Air, rely solely on USB-C charging, so the power supply is much more straightforward.

When to Buy a New PSU

A common question that comes up when discussing computer upgrades is when it is necessary to upgrade a PSU. The power supply in your computer should be able to handle the vast majority of upgrades like adding RAM or an extra hard drive. But you really need to double-check before making major changes, such as replacing the CPU or GPU.

Replacing these power-hungry components may exceed the limits of your current power supply. Be sure to calculate the total wattage required for all the components and then decide if it is time to upgrade. Beyond upgrades, replacing a PSU isn’t necessary unless your current one dies. But this is also very rare and may be due to another problem entirely.

Wrapping Up

Hopefully, you now have a good idea about power supplies and some different ways to check your PSU without opening the PC case. Remember that wattage is the most important number to look for. This will tell you how much power the computer needs to run all of the different components. Other than that, the PSU tends to be one of the most reliable components in a PC, so it should provide many years of trouble-free operation.

Frequently Asked Questions

How do you calculate how much power a PC consumes?

To calculate how much power a PC uses, you will need to measure the amount of amps it pulls. The easiest way to do this is with a power monitor, but you could also use a contactless multimeter with a line splitter.

Do you ever have to replace a power supply?

Power supplies typically last the life of a PC, but they can fail prematurely. The more common reason to replace a power supply is that the user needs more power for new components, such as a GPU.

How big of a power supply should you buy?

The simple answer is to purchase the largest power supply you can afford and fit in your PC case. You really cannot have too much power, so it is a good idea to go bigger in order to prepare for future upgrades.

Why do big-name manufacturers use proprietary power supplies?

Many large companies use proprietary power supplies, which makes them difficult to replace. They do this for a few reasons, but one of them is to use non-standard PC cases. They can also build power supplies that conform to the power needs of their computers.

Are all power supplies the same size?

No, beyond the obvious differences in wattage, there is also a difference in build quality between brands and models. Additionally, you can get power supplies in a few different sizes to fit the various PC case sizes.

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