Seagate drive not showing up

[notasandwich]

I recently installed a new heatsink for my CPU and ever since one of my three hard drives has been detected by the BIOS regardless of what I do. The drive in question is a Seagate Barracuda 7200.7 Plus ST3160023A 160GB and up until recently it worked perfectly fine. I doubt it is dead as I could clearly hear the internal engine start when I plugged it in and as I am typing this with the case open and all the drivers sitting outside the enclosure (free of any clicking!). I tried using the seagate tool as well as Disk Management but neither detect the drive either. What can I do?

 

[sonexpc]

disconnect all the Work HD ... only use this Seagate 160GB ... also try swap the Power cable and data cable with a work HD... the last thing is try to swap to a port is for sure working.....and if still not see by the BIOS..............then is dead..

 

[notasandwich]

I already tried resetting the BIOS and switching different power molexs in but nothing works