2 of 4 HDDs not seen after PSU swap

Aug 18, 2017
I recently swapped out PSUs and now 2 out of 4 hard drives arent being recognized (1 is an SSD). Why would that be?

Here are the details:
I wanted to add in my old GPU, 1050ti, and run duel GPU's. My old PSU didnt have enough power cables to run both GPUs so I purchased the Corsair. Hooked everything up and nothing. I did some cable chasing and the unrecognized hdd's did not follow the cables, both SATA power and data cables. I then thought maybe the power unit was faulty, so I hooked up a spare PSU my buddy had, an EVGA 750G3, still had the same HDD issues. I then unhooked the power to the old GPU incase for some reason the 750s were not up to the power task, still didnt fix the issue. I took the SSD that wasnt being recognized, put it into an external adapter and connected it to my MSI Laptop. The laptop recognized the SSD, so that ruled out it getting damged some how.

At this point I am pretty stumped. Any help would be appreciated.

Comp Specs
OS: Windows 10
Old PSU: Corsair CX600M
New PSU: Corsair CS750M
Motherboard: ASUS H170 Pro
GPU1: GTX1070
GPU2: GTX1050ti
HDD: 1TB WD Blue*
SSD: 750gb Samsun
SSD2: 500gb ATDATA
SSD3: 500gb Crucial*
*Not being recognized in BIOS or Win10
Check your motherboard manual on this, but it is possible that the SATA ports your "missing" drives are connected to are being disabled when you put the 2nd GPU in as they share PCIe lanes.
Are the drives still missing if you remove the 2nd GPU?