HDD problem help

JDC15

Honorable
Mar 15, 2013
1
0
10,510
this is a new build
specs: gigabyte GA-Z77X-UD4H motherboard, 120GB SSD, i3 CPU running windows 7 64 bit.

my problem is it won't see any other HDD connected. the build is up and running and i want to add a second HDD. i have two external seagate drives that i took apart to try to install. one is a 3TB and the other 1.5TB. i plug them into the mobo and boot, windows doesn't see them, go into the Bios, doesn't see them

things i have tried to fix it:
changing SATA mode between AHCI and IDE, nothing
tried changing the slot it was plugged into on the mobo between Gsata, and SATA 2 and 3, nothing
maybe the wire im using is bad, unplugged the SSD(that works and is seen) to use that power and sata cable and port, nothing
formatted and partitioned the drive, nothing.
to make sure i didn't damage the drives when taking them out, i put them back in the cases and used USB windows sees them as external.

i just at a lost as to what else to try. any help is greatly appreciated and thanks in advance