SSD boots over usb but not over SATA

Hi, I have a 2012 13" MBP running 10.8.5. Over a year ago, I swapped the old HDD with Samsung 850 Pro SSD, cloned my old HDD with Carbon Copy Cloner, and everything worked like a charm. However, yesterday, all of a sudden, my computer kind of froze, so I restarted it. And never reached the login window, got stuck at Apple Logo with spinning disk. Tried rebooting couple of times, but no luck.

- I can transfer my documents on my SSD with usb adapter, and it just works fine.

- I tried erasing and reformatting the SSD with the internal SATA cable to install El Capitan, but the computer cannot format when the SSD is internal and gives error about failed unmounting of the drive.

- If I connect the SSD with USB, it works fine, I can erase and format it, can install El Capitan or Mountain Lion, and can boot both of the OS over USB.

- I also attached my old HDD with internal SATA cable, and it boot and works just fine.

I am perplexed about this issue. It used to work until yesterday. SSD seems fine (it works over usb), SATA cable seems fine (it works with my old HDD). The problem only exist when the SSD is connected with internal SATA cable. I don't have any other SSD or computer to try other combinations. I appreciate any suggestions. Thanks!