How to check the hard disk cable?

I replaced the original Hitashi hard disk by the Seagate Momentus XT. I tried to clone my already working system with SuperDuper as well as Carbon Copy Cloner. With the both ways the system couldn't boot. A blinking folder icon with question mark was shown instead of the apple logo while booting.. blinking forever. However, I could boot it as external drive, connecting it via USB.. which is a sign that there is something wrong with the connection cable.

I have also tried doing a fresh installation, but also with no hope. The installation was always failed with an error message. However, the installation was completed successfully when I connect it as external.. which is a second sign. Also, I could boot it successfully via USB after the installation completed (still connected as external.) Once I connect it back as internal, the same booting problem happened again (blinking folder icon with question mark, forever.)

I have the feeling that the cable connecting the hard drive to the logic board has a problem. However, I don't want to pay for it before I make sure of that..

Any idea/suggestion is greatly appreciated.