White Screen on Start Up!

MacBook Air wont start up and stuck at white screen after chime. It wouldn't boot up on HardDrive and System Installation CD. I try to start using the System Installation CD but it stuck at white screen. I tried to start up the mac air without connecting the external optical drive and disconnecting the flex connector of the harddrive from the logic board which results and display a flashing folder and question mark.... I tried also to start the mac air with external optical drive with Mac OS X installation CD which gives me a CHIME... the APPLE logo and stuck at SPINNING WHEEL.... pls help...