The only way to know what power supply your PC has is to check it physically, or on your invoice
As we have already told you in the introduction, we have bad news: there is no way to know which power supply you have through software. The only way is in a physical inspection of the interior of the equipment, or failing that, check it in some type of invoice or document.
How to locate the font inside the box
The first thing you should know is the position in which the source is in your box. You can easily discover this from the outside, simply locate the power cable that you have plugged in and find where it goes, or alternatively the IEC power connector.
In some boxes, that connector may not be on the power supply itself, but there may be an internal extension cable. Nothing happens, follow it and you will find where the source is located.
Now, open the side cover of your case, usually the one on the left side (seen from the front) should be more than enough. However, depending on the box and the font, you will most likely have to remove both or just the right one to identify it. Do it without fear, with a screwdriver if the box requires it or, as happens in almost all current boxes, with your own hands you can remove the 2 screws from each side box.
Now, look where the power supply should be and locate it. This is done very easily, as a silver or black metal box will clearly stand out, from which you will see a good number of cables coming out to the other pieces of equipment.
Once you have found the source inside, it is time to identify its model based on the label that you find on one of the sides.
It may be the case that the label simply has the name of the brand and some letters that correspond to its model. In that case, you will simply have to search the internet for what you see and you will see its technical specifications, analysis, etc. And if you can’t find the power (in W) of the source, it may be on another sticker located on the opposite side of the fan.
What if you can’t open it?
If you can’t or don’t want to open your PC case, the only viable alternative left to you will be to look for your equipment’s invoices or purchase history. If you bought the parts in a store, you will most likely have a breakdown of each and every one of its components on the product invoice. Check the website where you bought it, the paper invoice or, failing that, check your email and try to find it.
Here, it is much easier for you to know what the original power supply model is. Since you will be able to know what exact model of PC you have, and access its technical sheet to see its basic specifications. This is something that can usually be done by software, and for this you will have to go into System Information (look for it in the start menu).
There, you should find System SKU or System Model. Some of the two data should be more than enough to find the exact computer model on the internet, and browse the file on the manufacturer’s official website. Surely it does not serve to know the exact model, but the basic specifications, at least.
Another option is to use the manufacturer’s own software that identifies your equipment. One example is Lenovo‘s Service Bridge , which automatically identifies your PC model and more.
Why can’t I know the power supply by software?
Let’s start with a fairly clear idea: for the power supply model to be known through software, there would have to be some kind of communication channel between the supply and the motherboard that allows it. There is?
The first logical idea that can come to mind is that a source is only there to provide energy, and not to exchange any type of communication. However, there are signals that are transmitted to the motherboard and are vital to its operation. Let’s see where they are and what they are, to see if they could give the source model data.
The only cable where there are special signals that could be “suspicious” of transmitting information to the equipment is the 24-pin ATX. In the photo above we show you what each one is, and we see several special ones. Specifically:
POWER_GOOD or PWR_OK: Used to give the board an alert that the power supply is malfunctioning. When it is turned on, it goes through a series of internal checks, after which it emits a 5V signal if these have passed well.
PS-ON: in this case it is used to know when to turn the source on and off, without further ado. It’s also a basic electrical signal: 0 or 1, high or low, there’s no more transmission than that.
As can be seen, none of them is a data channel, rather it is a simple electrical signal, flat, continuous, without any type of variation that allows the sending of any data.
Some of you may ask, and then how is it that I can know data from the source such as the output voltage through software? Well, very simple, because these measurements are made with sensors located on the motherboard and not on the source.
And what about pre-built PCs?
The information that we have given you above applies to a PC that works under the ATX standard. It governs the operation of all power supplies that can be purchased on the market.
However, in a pre-assembled branded computer (HP, Asus, Acer, Dell, Lenovo…) this standard does not have to be followed, and the manufacturer can modify its font at will. Will we see any special signal in these cases? The reality is that there is no such example, so unfortunately no, we did not find a way to know the font model by software on a pre-built PC. You will have to resort to the methods that we showed you before.
The case of laptops
In a laptop, the manufacturer has full power to design the power supply of the equipment in his own way. For this reason, each laptop has a specific way of being powered, which allows detecting if an inappropriate charger is being used.
In any case, when there are no warnings of this type, knowing the model of the charger will be reduced to checking it on the label that it has. If the brand it indicates matches the one on your laptop, it is most likely the original charger.
On the label itself, some of the useful information you can find will be:
Maximum power, based on multiplying the output value of voltage and amperage.
Efficiency level, divided into “classes”
Actual charger manufacturer. Your laptop charger is probably manufactured directly by another company.
This information is helpful when searching for a replacement or determining compatibility with other notebooks.
Final words and conclusion
Unfortunately, there is no way to know which font you have using software. Simply because there is no data communication channel between the source and the board that allows it. The only special signals that are transmitted are extremely basic, and not even the slightest data can pass through them.