Each of the cables and connectors in the box must be connected to its corresponding connector on the motherboard for everything to work properly, but there is a possibility that when assembling the PC you make a mistake when connecting them, and that you either connect a cable where it is not either do it with the reverse polarity (the cable reversed). Be that as it may, we are going to tell you what will happen to your PC if you do.
What is the function of each of the cables in the box?
With few exceptions, PC cases always have the same cables that we must connect to the motherboard. Obviously there are some box models that, for example, do not have a hard drive activity indicator and therefore do not have that cable, but as a general rule they are always the same:
- Power LED (or P LED): they are two connectors that are always individual, one with a positive and a negative polarity, and as their name suggests, they are used to activate the power indicator on the box.
- Reset SW (or RESET): is the two-pole connector that allows the reset button on the box to work.
- Power SW (or POWER): this connector, also with two poles, is the one that allows the power button to work.
- HDD LED: also two-pole, allows the hard drive activity light in the box to turn on.
Most boxes also have cables to service the ports USB 2.0 and USB 3.0, as well as another cable called HD Audio which is the one that works for the front microphone and headphone minijacks of the box.
What happens if they don’t connect properly?
We are going to omit the USB 3.0, USB 2.0 and HD Audio cables because they have a shape and with a specific pin grid and can only be connected in their corresponding connector, it is impossible to connect them wrong (if they were, they would simply not work and that’s it), so we are going to focus on the rest of the cables that the box brings.
To begin with, we are going to assume that they are connected to their corresponding port but it is done with the polarity reversed, that is, we connect the connector turned over with the positive in the negative and the negative in the positive. If you do so, simply its corresponding function will not work and nothing else will happen, although it is true that on some modern motherboards it does not matter the way you connect it because it will also do its function without problem. In this case, you should not worry about anything.
Now, what happens if you connect, for example, the RESET connector to the POWER connector? Let’s see it:
- If you connect the RESET to the POWER or vice versa, each of the buttons will simply do the function of the other, that is, the power button will reset the PC and the reset button will turn it on.
- If you connect the HDD LED to Power LED or vice versa, the lighting of these will work the other way around, that is, the power LED will blink with hard disk activity and the disk activity LED will remain on when the PC is. In some cases the power LED will stay on and will not blink, so you would have both indicators always active.
- If you connect RESET or POWER to the HDD LED or Power LED and vice versa, none of these functions will simply work, but nothing will happen beyond that.
So the moral of this article is that nothing really happens if you don’t connect the cables from the box to the motherboard correctly, they just won’t work or have reversed functions. With this you may also have guessed that if, for example, the power button on the box has broken, you could connect its cable to the reset button and turn on the PC with it (you would lose the reset button, but obviously power is more important turn on the PC, right?).