I spilled a drink!

I have a question. I spilled a drink on my Macbook air.. I have been on iservis and they made a diagnose for my macbook.. They said that display and top case have to be replaced... Okay that would be okay if the replacend wouldnt cost me 500euros... So i told them thanks but not thanks... Now i decided to repair it by my self.. And i started to wondering if its even possible to damage lcd display with liquid spilled over my macbook? Is it maybe the graphics card on motherboard the one that is damaged? I can turn on computer... And it looks like it works... But ofcourse i can't see nothing.. Is there a way to diagnose the problem? What is usualy the problem when you do some stupid thing like i did? :) I really dont wanna pay 500eur because parts on ebay cost me only 200eur and i can change lcd display by myself. Thanks for answers and I'm really sorry about my english writting :)

Cheers from sLOVEnia ;)