Q: MacBook Pro with Retina Display Issue

This is the Mac Pro desktop forum. I requested your post be moved to the MacBook Pro laptop forum.

If connected to a mag safe power supply. The computer should turn on even if the battery is dead. When you were able to boot, was this with or without the mag safe connected. Have you done ether a pram or smc reset.  https://support.apple.com/en-us/HT204063  https://support.apple.com/en-us/HT201295 Also check the magsafe.  https://support.apple.com/en-us/HT203207 Check battery condition.  https://support.apple.com/en-us/HT201585 Never run the battery down past 30%. You can also hold the option key while clicking on the battery icon(top right) to get condition.