Question PC not booting when i install a second HDD

[shadowXXe]

Hi everyone so my dad was having some trouble with his hard drive so I offered to take a look only to find that my pc refused to post/boot when the HDD was plugged in I tried to remove sata data to see if it still wouldn't boot but this time it did boot I'm honestly at a loss I have never seen an HDD behave like this and was wondering if you guys have any advice? (note my motherboard does have these Easy debug led's to diagnose boot problems and it stopped at vga)

 

[SkyNetRising]

my pc refused to post/boot when the HDD was plugged in

So - it just hangs in HDD detection phase and you can't even get into BIOS? For how long?
Anything shown on the screen?

 

[shadowXXe]

So - it just hangs in HDD detection phase and you can't even get into BIOS? For how long?
Anything shown on the screen?

No display can't get to BIOS