Macbook Pro internal HDD won't boot, but if i use it by usb works perfect

Hi people I have this computer with the following problem: The computer will not start if I left the hard drive internally, but the same hard drive boot the OS if I connect it by USB. I did the tests to verify the hard drive, but testing the hard drive they works perfect. I thought it was the hard drive connector, but the computer recognizes it but will not let me do anything to this hard drive. This hard drive is formatted in journals file system that everything works fine when connected by usb and boot the operating system but does nothing when connected internally only appear but you can't make any changes in the hard drive. When start the machine with this hard drive internally I get the error foulder with the question mark. The machine does the same thing if a connect a new hard drive. Anyone have any idea what can happen to this machine?