eli5: What actually happens when you “restart” a machine – does it switch off? If so how does it start itself again?

Question

eli5: What actually happens when you “restart” a machine – does it switch off? If so how does it start itself again?

In: Technology

Answer 1

The circuit that remembers to switch it back on doesn’t get switched off.

In something like a computer, there’s a little circuit which controls the power to the rest of the computer. When you press the button, it turns on the rest of the computer. When it gets a “turn off” signal, it turns off the rest of the computer. When it gets a “restart” signal, it turns off the rest of the computer, then turns it back on.

When you hard-turn-off the computer by holding down the power button, this is the same circuit that counts how long you hold down the button, and then turns off the rest of the computer.