ok it is a Desktop PSU is a Thermaltake TR2 RX 850W Model is TR2 RX-850AH3CH
DC output is +5V +3.3V +12V -12V +5Vsb
Bios power info is as follows
3.3V is 3.360V
5V is 5.035V
12V is 12.149V
VDDA2.5V is 2.532V
Those are good voltages (within 5% of what's supposed to be there).
I note from your Speccy that your BIOS is old.
Description SABERTOOTH 990FX R2.0 BIOS 2901
Improve system stability File Size 3.13 MBytesupdate 2016/08/05 Download from Global
Note how it says the latest version "Improves system stability". I'm not optimistic that the latest version of BIOS will fix your problem, however I HAVE seen a "BIOS refresh" make weird recognition problems go away. Also pull your CMOS battery and verify it's still putting out it's 3.3 volts (or whatever it is). If in doubt replace it.
Have you ever seen a situation where the Hard Drive was not recognized in BIOS, or is it just in Windows that it disappears.
Reason to ask is if it's not appearing in BIOS, then you have a very limited number of causes. Bad BIOS, Bad motherboard (could be SATA socket, trying moving cable), bad cable (reseat all connections), bad hard drive. Not showing in BIOS is hardware not software.
On BIOS flash:
If you have done it before and feel comfortable, I suggest you update BIOS to latest version. Just be aware that sometimes a bad BIOS flash can BRICK a machine. New BIOS saves a copy of the old BIOS now (they didn't used to), so the warning/disclaimer is more perfunctory now. If you've never done this and want assistance, mention that here and someone will help.
Edited by Aaron_Warrior, 11 June 2017 - 11:47 PM.