Why won't my new HDD mount?
1) Installed new HDD per ifixit DIY guide.
2) Went to install OSX (Snow Leopard) but the drive didn't mount so Disk Utility couldn't see it to format.
3) Rechecked connections and it still didn't show up.
4) Reinstalled old HDD and it mounts (disk is corrupt though)
5) For fun, we installed the new HDD in the external enclosure and it successfully mounted via USB. We formatted it (Mac OS Extended -- Journaled), took it out of the enclosure and reinstalled in the MBP, and the machine still doesn't see the drive.
Resetting the PRAM and SMC were attempted, but unsuccessful.
My brain is sad.