15. The component we need to install next is one that could be opened without damaging it, but it could be very dangerous for your health to do so. Also, it has a substantial impact on the noise level of your new PC. Which one is it?
From Quiz Computer components and PC building
Answer:
The power supply
Many cases come with a pre-installed power supply, but you should be sure to study tests and reports since case vendors often install cheaper devices that waste energy and do not deal well with inevitable small fluctuations of mains power. If the case of your choice comes with a noisy or inefficient power supply, try getting it without one. Also, when selecting a power supply, make sure it is strong enough to power all components, but do not overshoot - a 400 watts supply working at 80% is much more energy efficient than an 800 watts one working at 40%.
At this point, I also have a warning for you: Do not EVER open a power supply! Even after disconnecting it from the mains, several components still hold high voltage charges and can continue to do so for several hours. These charges are strong enough to give you dangerous electric shocks.