Problem SATA Cable or Motherboard

Sup, I have been having some problems with the connection between the Sata cable from the HDDs and the motherboard of my M18x R1, however, I do not know which one is the faulty one. The cable will not work if I put it all the way inside the connector (Flex cable not connected message in the BIOS), so I have to try setting it in different ways until the HDD finally gets recognized by the BIOS (sometimes it will recognize the HDD but will get corrupted HDDs errors). However, any strong movement of the laptop will cause the cable to move, which force me to start the process all over again. Another thing is that I can remove the Flex cable with minimal force when its seal is locked.

Even with the sudden disconnections my HDD have been going strong without any corrupt data, however, I will soon upgrade to an SSD which might not be that lucky, which is why I am trying to solve this problem first. I do not have another SATA Flex cable in order to test if mine is faulty, so I was wondering if, with the information provided, you guys can find out if I need a new SATA Flex Cable or a motherboard (connector) replacement (might as well upgrade to R2 motherboard).

This is the SATA Flex cable that I am talking about:

 

Bumpity bump.

 

Bump 10char.