The laptop is not turning on

Ok I would ask you this. is it like when turn it on, The display turns on for second and the whole laptop shuts down like fan and everything. or just screen shuts down. if it's the first case then open the laptop remove the battery and connect the charger only and then turn it on again. if it works then your battery might be at fault but it happens again same that mean your motherboard might be damaged take a voltmeter check all the ends of wires if you hear any beep anywhere which flows electricity that means that part is burned out or damaged in most cases you have no other choice but to change the whole motherboard.

if it is like 2nd case that means you just have to change the battery and you are good to go.

I would also ask did you by any chance open the laptop by any chance and somehow something metal part touched the motherboard while the battery wasn't fully connected or did you install any new parts like ssd or ram chip or even a wifi - bluetooth module?