IMAC bluetooth won't turn on

Lynn,

Please describe in more detail what you have tried and what results you are getting. Saying Bluetooth wont turn on is not a question and provides little if any useful information. In addition, please at least let us know the version of OS X installed on the computer. If you don't know click About This Mac located by clicking the Apple symbol in the upper left of the display.

Bluetooth devices become unresponsive

Same problem! Bluetooth will NOT turn on. More detail? there is a "turn on bluetooth" setting in system preferences>network>bluethooth PAN>set up device : "Bluetooth Off button that says Turn Bluetooth On is greyed out, and it does NOT work. Will not turn on!