> If your computer is not opening so firstly you need to check your switch is on or not on maybe your didn't on your power switch.
> You can check your power cable also. You can take out this power cable and put in another computer so like this you can check your computer power cable.
> Maybe your power cable port is not working.
> You can check your RAM also because some time because of dust RAM doesn't work . So you can remove your RAM and clean to pins of RAM .