bluetooth suddenly not available. cannot turn on.

Running iMac (mid 2011) 2.GHz intel core i6 4GB Yosemite 10.10.3

Bluetooth suddenly stopped working. Says "Bluetooth: Not Available" If I go to settings I cannot turn it on. I have

• tried to turn on from settings but cannot
• Restarted with all USB's unplugged.
• Unplugged for 5 minutes and plugged back in.
• deleted plists from library.
• Tried to run diagnostics holding "D" key down but did not work.
• Searched support and community for another solution