My MacBook cant start, nothing happens when i push the power Button. Battery is full loaded. What Can i do?

Go step by step.

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

Note: Steps 5 and 6

Step5

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".

Best.

If you are still under warranty and/or have AppleCare, call them. Let them deal w/it.

Otherwise, take the MBP down to your local AS or an AASP. Diagnostic testing is FREE!