Thank you for your reply.
Asus model is G74SX-AH71. There is this kit included in the box containing a board and a FFC sata cable for 2nd hard drive. I connected my SSD to the board and then board to laptop's motherboard input by the provided FFC cable. Turned it on, didn't work so re-opened the bay. Board and everything else look fine. But one line in cable is completely burned.
Since I was using it on my second bay, my old hdd was in the primary slot. So I could boot up laptop with no problem. But now I don't have the original ASUS FFC sata cable.
I have another one, which is 60v. Original one was 30v. I was wondering if I can use the 60v and try again or it bears some risks?