850 evo blue screen randomly..

[schpen]

Okay, so im posting for my cousin.. he got an 850 evo about a month ago, and the last day or two hes been getting random blue screens, and when he starts up his comp again, it wont boot or find the SSD. Bios wont find it or anything.. but if we unplug the sata cord from the motherboard and plug it back in, it boots up just fine. Anyone know what could cause this? His motherboard is 970 Gaming

 

[schpen]

16 reads and no replies? :/ anyone?