It is important to not stack boards on top of each other because you could accidently dislodge chip this way. It is important to remove loose jewelry because they might get caught in cables and components as you work. You install the drives first. The motherboard is installed so that the bottom of the board does not touch the case. If the fine traces or lines on the bottom of the board were to touch the case, a short would result when the system is running. Look closely at the board, you can see labels identifying the pins. To help orient the connector on the motherboard pins, look for a small triangle embedded on the connector that marks one of the outside wires as pin1. Look for pin 1 to be labeled on the motherboard as a small 1 embedded to either the right or the left of the group pins. If the labels on the board are not clear, turn to the motherboard user guide for help. The cooler sits on top of the processor and consists of a fan and a heat sink. A heat sink uses fins that draw heat away from the processor. The fan can then blow the heat away. 4-pin CPU fan header. To get its power, the fan power cord connects to a 4-pin fan header on the motherboard. The fan connector will have three or four holes. A three-hole connector can fit onto a 4-pin header; just ignore the last pin. If you use a fan power cord with three pins, know that the fan will always operate as the same speed. A power supply has wattage ratings, which are the amounts of power it can supply. These wattage capacities are listed in the documentation and on the side of a power supply.
Video cards draw the most power.