Dear XXXXX, than you for your reply. My problem is slight complicated. I am acting on behalf of my wife - her Macbookair she is far away at other country where the internet connection is poor; according to her it shows ? or and could not see the MacHDD when she tried to reboot/restart with option key.
it was bought 24 Oct 2012. MacAir 13.3/1.8/4/128 flash. ?snow lion
two things happened
1. Mac HDD does not appear... it only showed connecting network connection
2. when the external back up portable drive was connected it was shown on the screen but not the main Mac HDD. There was no other option so when this external drive was chosen the screen went to black and small circle was rolling.
Also tried boot from MacX Mac HDD cannot be chosen even try with (X) key
i do not think this has been tried yet.
Thank you for you help. It is quite difficult to contact my wife who is now at Myanmar where the internet connection is poor as well as telephone lines (both land line & mobile). I am acting on her behalf. I will pass your steps to her and see what happen. I will let you know the outcome.
with best wishes.
i will add it to her.
The MacBookAir is still not working. We will take it to Apple shop when she comes back from Myanmar as there is no Apple shop there. Thank you for your help. The problem is now beyond our reach and nothing we can do more. Now she is using USB stick as temporary HDD until it repairs.