Help: Laptop not firing up. Charger light goes off immediately when plugged

Hi,

I have a Dell Lattitude 6430. Recently, I am facing problems firing it up. Last, it gave me a warning that the battery is low and the screen shut off putting it in hibernate mode. Ever since, I have been unable to power it on.
I looked around the internet and found a potential reason could be that the motherboard has shorted.
Hence, I tried doing some continuity checks around various components and every time I heard a buzz.
I need some help around, what could be the potential reasons for my laptop not firing up? If it’s a shorting issues any links to assist me better in debugging the board would be helpful.