Can't turn on my mac book pro

Go step by step.

http://support.apple.com/kb/TS1365

Note: Steps 5 and 6

Step 5

Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

Keep it charging for 2 hours or more.

Best.