Question HDD only works when connected externally via sata-usb ?

[Premixed8]

Yesterday I was transfering files from an external drive to a WD Black in my pc, and while it was transfering my pc went to sleep mode. After it went back on, the drive was no longer showing up on windows explorer. I went and looked at the drive partition manager and the drive seems to be uninitialized. But when I try to initialize it I get a i/o device error. I have also tried using diskpart to fix it but that didn't seem to work. I am currently running the manufacturers diagnostic tool to see if that finds anything. Does anyone have any ideas as to how I could fix this? I can't even seem to format the disk as it won't initialize.

Update:
Result from diagnostic tool
Is there any way to fix this and recover at least some of the data on that drive?

Update 2:
After purchasing a USB - Sata cable it seems the HDD works, so probably the problem is with my SATA connection on my pc or something like that ?

 

[Premixed8]

So for some reason the hard drive only works outside of the pc when connected via a sata to usb cable to my pc. I was wondering, what would be physical reasons why my hard drive wouldn't work inside my pc but only outside?

(I also updated the thread name to match the real issue at hand)

 

[lvt]

Install Crystal Disk Info and check what it's saying about that HDD.

Btw did you try that HDD on different SATA header and cables?