Testing for hardware failure (damaged in house fire)

House fire damaged the keyboard and I am unable to power the device. The MagSafe light went amber and then green within a few seconds of plugging it in. I’m am not certain how to power the device because the power button was fried, and likely has water contamination. The innards are relatively unscathed. What would be the most effective method of troubleshooting the logic board, power management, etc so that I know what needs replacing?

Not going to believe this but I actually got the thing to power on. Melted keyboard and all. Plugged up the old magsafe power brick and it powered on. The screen backlight is all jacked up though. LCD seems fine. Anyone know if the backlight can be separated from the LCD and replaced?