Motherboard not detecting 3.5" HDD

[theplatinumhawk]

Hi.
I've recently built my first computer and I've run into a problem with my 3.5" HDD not being detected by the motherboard. I've tested a 2.5" HDD and it works fine, I've tried switching around the SATA cables and putting them in different slots but still no luck.
It's a 1TB Wd Blue 3.5" Hdd and the motherboard is an ASRock B250M Pro4.

 

[cin19]

Do you test the 3.5" HDD in other computer? Is it new one or used one?

 

[theplatinumhawk]

I have just tried it in another pc and it isn't being detected. It is a new one so does this mean it's faulty?

 

[cin19]

Yes. Return for replacement.

 

[theplatinumhawk]

Yes. Return for replacement.

alright, thanks for your help.

 

[theplatinumhawk]

I've just gone and got a replacement and the motherboard still isn't detecting the hard drive. It is spinning up and all. just not detecting. I have tested it and made sure I've installed all the drivers for my motherboard.; so by the off chance have I been given another faulty hard drive or am I doing something wrong?

 

[cin19]

If you did test the HDD in two PCs, and the HDD can't be recognized, I will say it is DOA again.

 

[USAFRet]

I've just gone and got a replacement and the motherboard still isn't detecting the hard drive. It is spinning up and all. just not detecting. I have tested it and made sure I've installed all the drivers for my motherboard.; so by the off chance have I been given another faulty hard drive or am I doing something wrong?

And you have both cables connected?
What other drives are in this system?