Try resetting the SMC http://support.apple.com/kb/ht3964
1 Choose Apple menu > Shut Down.
2 After your Mac shuts down, press Shift-Control-Option on the left side of the built-in keyboard, then press the power button at the same time. Hold these keys and the power button for 10 seconds.
3 If you have a MacBook Pro with Touch ID, the Touch ID button is also the power button.
4 Release all keys.
5 Press the power button again to turn on your Mac.
Try resetting NVRAM/PRAM http://support.apple.com/kb/ht1379
1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Press and hold the Command-Option-P-R keys.
4. Turn on the computer.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.