Reusing cables from an old power supply can be your downfall

With the appearance of modular power supplies, the most enthusiastic started to buy them. The problem arises when they decide to upgrade their computer, buying a new modular power supply. If the new source does not have cables that the old one did, the user decides to reuse the old ones in the new one.

This practice can cause serious damage to your equipment, so pay attention to what you will see below because it will be of great help.

Index of contents

It all starts with the source connections

The cables that can give more problems when mixing are molex or SATA, the PCI express to power the graphics and the one that powers the PC. It all starts with the cable squares because each one has a function and it must be made clear so as not to produce a short circuit.

Reusing cables from an old source to a new source, and vice versa, can burn our components, such as rendering hard drives unusable or causing a short circuit in the graphics card, for example.

In any modular cable we find two ends: one that goes to the power supply and the other that goes to the device port, which can be the hard disk, the graphics, the EPS12V port or the ATX. This end is not going to be a problem for us; however, the end that goes to the source is the one that can detonate the overload and burn the component whose cable conflicts.

Modular power supply ports are typically 6 or 8 pins. Many use the 6-pin connectors to save costs, as is the case with some Mars, EVGA, Corsair or Thermaltake.

The result of mixing cables

Figure 1: Power supply port

By reusing cables from other sources, we can cause a short circuit or not, it all depends on the cable. So, with knowing a little basic electricity, we will know when the cable can be reused and when it cannot. In the photo above we can see the modular slot of a new source that we have purchased. As you can see, each quadrant has a function.

The correct thing would be to connect in this port a cable that came with the new source that we have bought. The main reason is to forget about "stories" and have our connections secure. However, we can find cables from other sources that physically fit, but electronically are not compatible.

Therefore, the most recommended would be to connect a cable that came in the box, as we see in the following illustration.

Figure 2: Connecting the cable from the new source to it

But, you have not entered looking for this, you want to know what happens when we reuse or mix cables from different power sources. The theory is that a misfortune can occur, like nothing happening and working perfectly. Everything revolves around polarity.

On the other hand, you can contemplate a bad scenario, such as the one we explained to you through the last figure.

Figure 3: Old cable connection to new source

As you can see in the image, the shots do not fit, so they are not compatible. This means that a short circuit occurs. How does it occur? We connect, for example, an SSD that is 5V. The source wants to deliver 5V to the SSD, but the cable has an empty quadrant in there. In this way, everything ends in a reverse polarity. Here are two possibilities:

Our source is of good quality, so it protects itself with OCP ( Over-Current Protection ) or OVP ( Over Voltage Protection ). In this way, it prevents a short circuit or overvoltage in the circuit. If this happens, immediately turn off the power supply from behind. Our source is of poor quality, so it has no protection whatsoever. Therefore, the short circuit occurs and the catastrophe begins, which you can imagine.

Why don't brands make compatible cables?

The first question that occurs to us is this, since it is a fact that can cause serious damage, causing a fire. Unfortunately, power supply manufacturers don't come together to make compatible cables because they are supposed to supply you with the cables you need in the power supply box.

What seems more serious is that they manufacture physically identical cables, but they are not compatible. All this they do to save costs, but this problem is more frequent than is believed because there are already many users who have lamented the loss of its components in forums, such as Reddit.

In the event that you have many loose cables from both sources, it is best to put each one in its corresponding box so as not to confuse and mix them. If you do not keep the box of your power supplies, you can take two plastic bags, put a name tag on it and put the cables in the corresponding one.

We have made this article to advise you and urge you not to reuse cables from different power sources because, due to the reverse polarity, you can seriously damage your computer. So, use the ones that come with the font that you have bought to be able to enjoy the PC safely.

We recommend reading our guide on the best power sources

Have you ever reused cables from other sources? Has the article helped you? Share with us your opinions!