I decided to take out the logic board because I had a water problem. As you can problably guess all the componentes from both sides of the board, near the ventilation, were dirty with some green and white stuff so I cleand it all up with isopropilic alcohol. I assembeled it buck up and it turns on but it doesnt run the osx, screen doesnt turn on, you cant hear the welcome sound every time you turn on a mac and the only thing you can hear is the fan spinning faster and faster until it reaches its top speed and it stays like that. what can I do to fix it??