Hi guys! Today, my MacBook Pro 13" Mid 2012 (with Samsung evo 840 sad) started having serious problems out of nowhere to boot properly. I just got a flashing question mark when i tried to start my Mac. Doing some searching I found the following article by Apple: https://support.apple.com/en-us/HT204323 Unfortunately none of this helped because I wasn't able to delete or even repair the volume. Even worse, the volume doesn't appear on disk utility any more. So I decided to put the ssd into an external hard drive slot and voila, the ssd showed up again, I deleted it and installed OS X Mountain Lion through the Internet recovery. Everything went fine there. After the installation was completed I inserted the SSD into the MacBook again. First boot up, still perfect. But after a second reboot I am back at the beginning. Question mark appears again and in the Internet recovery menu isn't any sign of the ssd. Can't choose any drive At this point I am kind of perplexed and looking for some advice. Thanks in advance!