How to Fit the Internal Cables
You’ve installed the motherboard and power supply, slotted in the processor, and fitted your RAM modules – now it’s time to connect it all together. Accuracy for this step is vital, as any mistakes will mean your PC may not work as it should – or may not start at all.
To get your PC to turn on when you push the power button, you need to connect the power switch to the motherboard. Among the loose cables in your case, you’ll find a two-pin connector. This will usually be marked PWR SW, but check the case’s manual if you’re not sure.
This needs to be connected to the power jumpers on the motherboard. Typically, these will be located on the bottom-right of the motherboard and will be marked, although you should double-check your motherboard’s manual to make sure. The connector will just plug over the two pins and should connect easily.
If your case has a reset switch – not all do – then there will be a similar connector to the power switch, with RESET SW written on it. Connecting this to your motherboard lets you restart your PC after a major crash, as it resets the hardware and forces your computer to reboot.
To connect it, you need to find the reset jumpers on the motherboard. These will be near the power switch, but you should read your motherboard’s manual for an exact location. Simply push the connector over the two pins to connect the switch. It doesn’t matter which way round this connector goes.
3. Power and HDD LEDs
The HDD connector connects to an LED on the front of the case and lights up when the hard disk is in operation. This is useful, as you can see whether your PC’s working or if it’s crashed.
As this connects to an LED, it must be connected correctly. The cable should be marked as positive and negative (this is usually written on the plug). The motherboard HDD jumper will also have a positive and negative port. Check your motherboard’s manual carefully to make sure you get this right, and then connect the cable.
Do the same thing for the power LED, which will have a similar connector. This must be connected the right way round, so make sure you get the positive and negative connectors aligned.
If your case has front-mounted USB ports or a card reader, you’ll need to connect these to spare headers on your motherboard. In all likelihood, the cable in the case will be marked USB.
Your motherboard will probably have spare connectors marked USB, but the manual can tell you exactly where these are. USB connectors take power, so you need to plug the cable in the right way round. Fortunately, the USB ports on most cases have a single plug that can only be connected to the motherboard in one way. If it doesn’t, you’ll need to check the case’s and motherboard’s manuals carefully to make sure that you install the connectors correctly.
Assuming you’re using a block connector, plug it into a spare USB header on the motherboard. We’d recommend using the closest header to the cable to avoid draping cables everywhere.
Front-mounted FireWire cables plugin much the same way as USB cables. Again, look for a spare FireWire header on the motherboard (the manual will explain where these are), and then connect the FireWire cable to it. The cable may be marked as 1394, as FireWire is also known as i1394.
Front-mounted audio ports also need to be connected to the motherboard if you want to be able to plug in your headphones and a
microphone. Fortunately, most motherboards and cases have a single block connector that plugs into the front audio connector on the motherboard.
Your motherboard’s manual will have full details of where this is connected, but it’s usually located by its back panel. Again, there’s only one way to connect this cable, so just slide it gently into place. If your case has a Speaker header, plug this into the appropriate connector on the motherboard. This is used to give warning beeps.
It’s common for modern cases to have extra fans pre-fitted. These help increase airflow through the case and keep your PC cool. While fans can be connected directly to the power supply, it’s better to connect them to spare fan headers on the motherboard. This way, the motherboard can automatically control the fan speed and keep your PC running as quietly as possible.
If your fans end in three- or four-pin connectors, you can plug them into your motherboard. Look at the manual to find a spare fan connector and then plug in the fan’s power connector. Three-pin connectors can plug into four-pin ports and vice versa. The cables can also plug in only one way, so it’s easy to get it right.
8. CPU fan
The processor fan, which we installed earlier, can now be connected to the motherboard. In the same way as system fans, the processor’s fan speed is controlled by the motherboard based on the processor’s temperature. This keeps your computer as quiet as possible.
There’s a special connector for the processor fan on the motherboard, which is often called CPU FAN. Check your motherboard’s manual for its location. This is likely to be a four-pin connector, but three-pin processor fans can also plugin. The connector can go in only one way, so just plug it in.
Once everything is connected properly, ensure that the cables are secured and in a safe place. You don’t want your cables to get caught in any fans. Using the empty drive bays and zip ties, you can secure the internal cables in your newly remodeled PC.