Now you will need to connect the main motherboard power cable from the power supply unit to the motherboard socket, this is a large rectangular socket. Next connect the power switch and any other remaining cables. Usually you would connect the power and reset switch, power LED, hard drive LED and PC speaker (Buzzer) cables.
The connecting cables can be found running from the back of the case’s front panel. They are usually clearly labelled, but you should check your case and motherboard manual for the correct orientations.
Below is a brief illustration.