The camera may not turn on if the lens portion is rotated too quickly. Move the lens portion back to the original position and then try rotating it a little slower.
If the issue is still unresolved, service may be required.
For all Sony products (EXCEPT VAIO computers): To send your product to a Sony facility to be repaired or to check the status of the a repair, visit our eService web site.
For VAIO Computer products: Please call 1-888-4SONYPC (476-6972) for service information for your product. To check the status of your VAIO product repair, have your phone number or Best Buy service number available and call 1-800-433-5778.