A flashing folder with question mark I have a rather strange problem with my  MacBook Pro (13-inch, Late 2011). Whenever I start my computer I see a flashing folder with a question mark. I know this is supposed to be a common problem wich can be usually solved by the solution provided by Apple support.

However, my issue is different. Here is how it all started: I wanted to install Windows using bootcamp. The installer complained that my hard disk was corrupted and that I need to repair it using the recorvery HD. When I tried, I was asked to provide the firmware password. Since I did not have it ( I wrote it it on a piece of paper that I did not have access to at the moment), I went back and restarted my in target mode so I can back up my documents on another mac. Unfortunatelly, after restarting in target mode, I was asked to provide the firmare password again. When I finally got the password, my computer restarted with a flashing folder with a question mark. 

I have tried all troubleshooting available on the internet and nothing seems to work. Some people think that I need to replace my internal HD cable. However, how can this be? I didn't mess up with my hard disk at all. During the troubleshooting, I used a bootable hard-drive, and notice that I could no longer see my HD in the list of available hard-drives. It is like it is completely gone. Can someone please suggest any solution? Please keep in mind that I live thousands of miles away from any Apple store. I can't get any official support. I have to fix this myself.
It would seem that the drive is no longer "blessed".

First, try booting the Mac while holding down the option key and if the drive is in the list of boot devices then selecting it once will "bless" the drive and you should be able to boot off it once again.

If that doesn't work then boot off the bootable hard drive you mentioned and run Disk Utility which can be found in /Applications/Utilities and you should be able to see the drive in the drive list. Once there you can try to first verify then repair the disk.