Installed new PSU, HDD not appearing in BIOS

[Quantum]

SPECS:
CPU: Intel i5 4460
GPU: AMD Radeon R9 290X Direct CU II OC Edition 4GB VRAM
Cooling Unit: Corsair water cooling unit with two 120mm fans, don't remember the model number
PSU: EVGA Supernova NEX 650G
OS: Windows 10
Motherboard: GIGABYTE Z97X-UD5H-BK
HDD: Seagate 2TB
SSD with OS on it: Samsung EVO 840 250GB
Other SSD: Samsung EVO 850GB
BIOS Version: F8
Other: I have a regular $20 optical drive

Also, I am NOT overclocking.

I'm about to go mad.

I installed a new PSU today to combat the irritating issue I had when playing games - it would restart at random points in game. This got very annoying so I bought a new PSU at the suggestion of someone on here.

I connected the massive 24-pin connector to the motherboard and to the PSU, the PCI-e things to the GPU and the PSU, the CPU connectors to the motherboard and to the PSU, and the power cables for my optical drive, SSDs, and HDD to the drives themselves and of course the PSU. I also connected the SATA cables to each of those drives.

When I go into BIOS, I only see my optical drives and my two SSDs. My HDD is nowhere to be seen, on BIOS or in Windows. It's not in the Device Manager either.

I've swapped SATA ports, SATA cables, even tried the other power cable from the box of my PSU. Same result: all drives are being recognized EXCEPT for my HDD which maddeningly contains all my music, video games, Steam, Origin, etc.

I've tried to turn on the computer and keep my HDD out of my case to see if it's functioning at all. As far as I can tell, the disk isn't spinning, which means I may have somehow fried my hard drive, but how???!!! What did I do wrong? And why is it only the HDD that isn't functioning?

I'm about to lose it. Any help is appreciated.

[joetheplumber68]

I had the same problem. New PSU and new HDD for expansion. Took several attempts and finally able to get it recognized in "Disk Management" by running a separate power cable from PSU to HDD. My Corsair ribbon style cable was stressed and simply not making a connection. It was a pickle at first then finally able to get power by not sharing any power cables with HDD.

[Quantum]

Originally posted by joetheplumber68:

I had the same problem. New PSU and new HDD for expansion. Took several attempts and finally able to get it recognized in "Disk Management" by running a separate power cable from PSU to HDD. My Corsair ribbon style cable was stressed and simply not making a connection. It was a pickle at first then finally able to get power by not sharing any power cables with HDD.

Ok, I'll try that. Thanks man.