Black Screen after a thorough cleaning?

I have a Mac Book Pro that I was given to service. What had happened, was that a full glass of red wine was spilled accidentally into the keyboard, thus ruining the computer.

I've given just about everything an incredibly thorough Isopropyl (Alcohol) cleaning. I replaced the Keyboard and put everything back together, making sure all the screws were put back correctly, and that the connections were solid.

However, to my surprise, even after the cleaning and even double checking of connections...It started; I could hear the boot tone, and the fans and HDD were spinning, but the screen was acting like it wasn't getting power.

All my connections have been triple and quadruple checked. I peeked at a couple of areas that may have gotten something in them (GPU & Processor) which was not possible. I reset some of the commands. I even ran a RAM test (Removing the RAM, then starting the computer) and that worked the way it's supposed to.

I've done nearly everything but bring it to another repair service (Which I'm not, because I'm the service for another, very patient, person).

However, even after a week and a half of trying to troubleshoot (Even looking online, which I'm not prone to do too often) I'm still stuck in the same pit.

I'm preparing for the worst however, like someone saying it's the motherboard (Or logic board, however you like to say it) at fault. That would ruin my week. But hey, things happen.

I'd be happy if anyone might be able to come up with a solution. This thing's been driving me crazy, even in school.

And if anyone needs to know, I am not a professional repair service (Though I understand the repair terms like a champ), I am a one-man team, and I can give any more information that is needed.

Thanks. -Andrew

Model No.: A1286

Serial No.: C02JFAXJDV33

Pictures that were requested:

I took one of the motherboard with all the cords still connected, one without the cords connected, and one of the back. Hope these suffice!