keyboard mouse usb no response on my mba

[batecam79]

For some reason,i shot down my mba,and i hold shift key to force the mba enter the safe boot,but when mba finish safe boot and ask me to enter password,i found my keyboard and mouse no response to me,and kayboard backlight are also dead.So i hold the power 5 sec force mba shot down,but when i restart mba normaly the problem still there.
Can someone help me out??thinks a lot!!!

 

[SFStateStudent]

You might need to do a reinstall via Remote Disk from another computer using reinstall discs. Give AppleCare a call and they can walk you through it if you are unable to do it yourself...🙁