Your issue is described in the video
"This computer has been passed onto me from my brothers. There are keys missing in the keyboard and I assume internal damage. It worked for me about a month ago. Whenever I try to start it up it beeps. Because the screw was loose in one area on the back I opened it up and cleaned it with alcohol and a paper towel gently...When I opened it up and noticed there was a redish brown dried fluid. (Probably dr. Pepper knowing my brothers. ) My friend who currently works at a computer shop turned it on earlier and there was beeping so the cleaning I did didn't cause the beeping. She said she could order a new keyboard for it but that isn't my main concern... It won't boot u"
Of course it won't boot, has a spill and keys and screws missing, not taken care of properly, what did you expect? You can try different RAM, taking the thing apart, cleaning things up, re-installing heatsink with new thermal paste. A bad keyboard connection or keyboard can cause systems not to boot. And you already said it has damage to the thing, unless you want to start buying parts like keyboard, motherboard, new RAM, I'd just sell it for parts.