Contribution d'origine par : Darrell Lindsay ,
PRAM reset is the only thing that has worked for me when I’ve had this issue. For those who haven’t done that before, these are the steps: # restart # as soon as you have a black screen (before the power on ‘ding’), hold “command” + “option” + “p” + “r”. # allow the machine to restart for a second time. # release the keys.