|"Yesterday our computer was acting up."|
We need more details.
An Aspire can be a laptop or a desktop computer model - which is it ?
It's extremely unlikely there's anything wrong with the power switch if this is a desktop computer, however, the case button that presses on it can get stuck such that the switch is depressed when it shouldn't be. If the button isn't sticking , it's a lot more likely the computer's power supply is in the process of failing, or the cpu is overheating.
If the power supply is in the process of failing, you can get all sorts of symptoms - one of them is the computer will not start up every time.
If the cpu is overheating, the computer won't start up again for a while after the computer has shut itself off, until the cpu has cooled below a certain temperature.