Existing HDDs are not recognized after adding new HDD

[chropass]

I'm a noob to unraid, I bought and set up it last week using my old unused components.

It was running with two of newly purchased 16TB HDD.

And I installed two of old 1TB HDD.

However, after that, the 16TB HDDs went missing and are not recognized (Added ones seems working ok so far)

Also, I'm not sure if this is related to this issue but the server's video output is kind of unstable.

It sometimes working normally but sometimes not. So far, once it worked at booting, it does al least until it powered off.

 

Here's what I've tried so far;

• Reboot (so many times)
  • Dosen't change the result
• Disconnect added two HDDs (same as before the adding).
  • No HDD recognized.
• Change connected sata ports, or cables
  • Both 16 HDDs are not recognized.
  • 1TB HDDs are recognized no matter what cable I use or where I connect it.
• Install old graphics card (radeon something. I did this just to get the video output...), with both 16 TB HDDs connected and both 1 TB HDDs disconnected.
  • Only one of 16 TB HDD is recognized.
  • No video output from both the motherboard and the graphics card.
  • Cannot reproduced so far.
• Same as above, but also 1TB HDDs connected
  • 1 TB HDDs are recognized. None of 16 TB HDD is recognized.
  • Video output worked but only after unraid is launched, not anything before it like BIOS.
• Look into dmesg output
  • Not recognized HDDs are not recognized here too.

I want to check BIOS to see if HDDs are recognized here but so far I cannot because of the video output issue.

The results are also may be differ (e.x. only one 1 TB HDD is recognized even though two of them are connected)

 

Here's components I used for the server

• Intel core i7 4790k (old stuff)
• Asrock Fatality H97 performance (old stuff)
• 12 GB of Ram
• some radeon graphics card (old, forget the detail but good enough to run some 3d games)
• Two 16 TB HDD (brand new, not refurbished)
• Two 1TB HDD (old)
• 600w ATX power supply (brand new, not refurbished)

Am I using a broken component or some set up issues??

Anyone have any idea to fix it or how to analyze the issue, please help me to do it.

 

[JorgeB]

Without video output this is not going to be easy to troubleshot, so see if you can resolve that.

[chropass]

Ok, I will try to resolve the video issue.

I got another unused graphics card so maybe swap to it.

If I got the video output back, what should I look for?