2 SATA drives refuse to work together

[matains]

Adding second hard drive results in the first (system ssd) disappearing from bios boot priority list. Not changing anything else, just attaching power and sata cables to the hdd. If i detach any of the drives the other one will appear but not both at the same time. Cannot think of any logical explanation to this myself.
Edit:
Motherboard model is asrock 970 extreme3
Drives are samsung 850 evo 256 gb and seagate barracuda 1tb

 

[Mr Kagouris]

Try different SATA ports on the motherboard.

 

[matains]

Try different SATA ports on the motherboard.

already tried, only changes which of the two remains visible in bios. I should update that it worked fine in current configuration until my OS broke down.

 

[Shaun o]

Matains.

Out of the Samsung 850 256Gb drive.
And he Seagate 1 TB drive.

What drive holds the working OS, the SSD drive, and is it connected to the first Sata port of the motherboard listed ?
Have a check.

As for the Seagate drive make sure it is connected to the second Sata port of the motherboard.
If it is the new drive and you have just bought it.
Then it will not have been formatted.

In your bios check the Sata mode for the Sata ports of the motherboard is selected right.
You should see and option also where the boot order of devices is for the type of hardware detection of hard drives.
It may be called CSM mode in the bios.

Enable the option in the bios settings, and set the detection order to - Legacy op rom/ Uefi booting and detection of drives.
If you scroll down the boot order page you will, or may see two more entries for boot able hard drives, and the booting order.

Set the boot drive with windows Os installed on it to number 1.
And any other device you wish to be detected for boot records. 2.

Save the changes before you exit the bios setup.
As long as both drives are connected to the same bank of coloured Sata ports of the motherboard, and not connected via mixed coloured Sata ports of the motherboard.

It should work after that.

Don`t forget that if you have not formatted the Seagate 1TB drive it will be likely that it will not show in windows under my computer.

To format the new drive use disk manager of windows OS.
Or if you have a boot able usb, or dvd install of the windows setup and install for the OS.
Boot from it, and let setup run.
When you gate to the point where windows asks you where or what drive you wish to install windows too.

You should see the 1TB drive listed.
Hi light it.

Then click on the advanced drive option writing ect in blue.
Format the 1TB drive, selecting the type of format, either Ntfs or Gpt.

Once done Matains, Do not press next, simply exit the windows install and setup of Windows.
By pressing the escape key on your key board.
and confirming you wish to exit the windows setup.

After the system restarts you should see the SSD drive listed along with the 1TB drive.
And the 1 TB drive will also be seen and show in my computer of windows OS once loaded ok.

 

[matains]

Thanks! I'm not sure at which point the problem was solved but now both drives are back. It's weird since both drives were working fine until today. Might as well been some random bug or hardware giving up. I'll just hope it stays like this.