Hello how are you? There are many causes due to which your computer wont turn ON.
-> It is possible that you power button has been disconnected from the wire so uncover your CPU and see. If it is then econnec it properly.
-> May be your power socket is not working properly. So make sure that power is going on you home socket.
-> May be your computer's internal power cable has been disconnected. So remove it from the power connectors on your motherboad and clean any dust and then connect it.
-> May be the outer power supply cables which are connected to your CPU power supply is not working properly so check it will different power cable.
-> Last it is possible the POWER SUPPLY is not working properly. So let any technition to test your computer's power supply.
REMEMBER TO UNPLUG THE MAIN POWER CABLE OF YOUR COMPUTER FROM THE SOCKET OF YOUR HOME.
Hope this will solve your problem. Take care of you and others and dont worry and be happy
Bye...
Dur-E-Wahab