335 Views 1 Reply Latest reply: Feb 23, 2013 5:48 AM by BGreg
You've probably already rebooted the system.
Reset your SMC and PRAM.
- Shut down your Mac.
- Locate the following keys on the keyboard: Command (⌘), Option, P, and R. You will need to hold these keys down simultaneously in step 4.
- Turn on the computer.
- Press and hold the Command-Option-P-R keys before the gray screen appears.
- Hold the keys down until the computer restarts and you hear the startup sound for the second time.
- Release the keys.
If that doesn't do it, see this Apple note on ports.