Hi guyse, I have a bit of a problem here: I’m running OS X El Capitan on a 2013 MBA. A couple of months ago I noticed that my MacBook would crash after about 30 minutes every time I would try to do a time machine backup (red flag!) Then my system started crashing regularly, just freezing to death in a weird way after running for 20–30 minutes, every single time. I backed up all I needed on an external HD, created a bootable installer, booted from it and used disk utility to erase my internal HD. And after that, the internal HD was just GONE — completely. Not available for the install, Disk Utility doesn’t see it. I installed OS X on the external drive, tried running Disk Utility and Disk Warrior from there — to no avail. System information doesn’t see the volume either, but under SATA it can see "Apple SSD controller". Alas, under Apple SSD Controller, there is just an "Unknown". No trace of my Hard Drive. Do you have any kind of recommendations before I bring the device to an Apple Store (way beyond warranty). I have a feeling like my HDD is closer to god now. Thanks in advance!