Hello guys! I have a mid-2012 13" MacBook Pro, and since a few weeks ago it started lagging a lot, so I took it to the support, and they told me that most probably it was a HDD, SATA cable or logical board problem. And after investigating the problem, they ended up telling me that it was a HDD failure. So I took my MacBook back and bought a new Hitachi (same brand as original) 500GB SATA 3 (6.0GB/s) HDD. Well, you may be wondering why I didn't get a SSD, that's because I'll sell this MacBook very soon, actually I was about to sell it when the problems started... Ok, continuing, I perfectly installed the new HDD, and holding Command + R, I turned it on, so I could proceed to internet recovery, as it didn't come with the OS DVD. And here's the problem, when I opened Disk Utility to format it, it didn't show up in the list, on the left side of the screen! As if I didn't have any HDD connected at all! The weirdest thing is that it does recognize my old and broken HDD, it doesn't even boot the system anymore, gets stucked on Apple's logo all the time, but it's still recognized! I have no clue on what to do now! I don't think this new HDD was already dead when it was delivered to me, cause it was intact, it's a quality product and I never had any problems like this before, I'll try to get a SATA to USB adapter, so I can test it properly on my PC! Is there anything I should try? Do you guys know if there's any solution for that? Thank you so much!