HDD disconnected at night

[JSTQ]

I left my pc running at night with some app launched from disk G, and at the morning I see that disk G is disappeared and app froze. I opened device manager, renew hardware config and it appeared back.

Why did that happened? Its not a first time, last time it was maybe half a year ago when I was watching a movie iirc, from other hard drive.

My motherboard is asus z-87k. I'm not sure what is the hard drive name, because I have two 2TB drives, one is seagate and other is hitachi. Not sure which one is "G"

 

[SkyNetRising]

Check health of your hard drives.
Use HDtune health, post screenshots.

 

[JSTQ]

2 2tb drives, one of them disconnected at night:
st2000vx000-1cu164 http://i5.imageban.ru/out/2017/05/08/3afd58f57f4080192300b311286c8643.jpg
hds5c3020ala632 http://i5.imageban.ru/out/2017/05/08/18fb3ff830707ce9a8424b1183f37f0e.jpg
1 tb drive, wasnt used, didnt disconnected
hds721010cla332 http://i3.imageban.ru/out/2017/05/08/b67c080a6fbc640ae605edc1a19cad5b.jpg

 

[SkyNetRising]

This one needs cable changed:

This one is seriously damaged. Start thinking about replacing it:

 

[JSTQ]

How do I check if SATA cable is bad? I have a bunch of old ones

 

[SkyNetRising]

How do I check if SATA cable is bad? I have a bunch of old ones

Better just to get a new one - SATA3 certified.