Replaced screen, will no longer power on.

Alright so about a month ago I brought my Macbook Pro to get the screen replaced. It was cracked I bought it from my friend who got a new one after his sister stepped on it. I used it for months before actually going to get the screen repaired. I was told a week after dropping it off, it's turned into over a month so I went to take it back no matter the condition. THe problems the guy ran into were; bought wrong screen, ordered a new one, back light wasn't working, bought a new wire for the back light, now both the new screen he bought, and the cracked no longer work.

The laptop doesn't even power on now.

Symptoms:

-No picture on screen

-No keyboard light

-No Apple light on the back lighting up

-It's fully charged, the side lights light up and say it's full.

-If I hold the power button hard, the disc drive will turn on but nothing else.

I attempted putting a disc in while it was starting to move and it accepted the disc and started to spin I hit the eject button and it came out.

-I heard the HDD start up once or twice then instantly shut off.

I have no idea what a hack this guy was seeing as the wire to the logic board won't even stay locked in anymore.

So please help!!