Q: Assumer un défaut de fabrication

The symptoms you describe are usually a problem with the internal storage.  Have you checked your Hard Disk Drive with Disk Utility>First Aid using the Recovery Partition?

Ciao.

Are you using Startup Manager to access the recovery Partition?

http://support.apple.com/kb/ht1310

If that does not work you can try using an external boot drive or Target Disk mode.

http://support.apple.com/kb/HT1661

The problem may not be the Hard Drive but the connection.  You can take out the Hard Drive and install it in an enclosure.  Connect it to the MBP via USB and the boot the MBP using Startup Manager.  If it boots the MBP, then the SATA cable is probably faulty and should be replaced.  If it cannot boot the MBP, probably the Hard Drive needs to be replaced.

Ciao.

I will give you the directions for the third option as best I can.

You will need a 2.5" x 9.5 mm SATA enclosure.  Here is a sample of many that are available.  It does not have to be an expensive one.  Any of these will work.  There are many vendors that sell them.

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100008040 600006255&IsNodeId=1&name=2.5"

You have to take out the hard drive from the mac and install it in the enclosure.  This video shows how to take out the hard drive from the Mac:

http://eshop.macsales.com/installvideos/macbookpro_13_unibody_mid12_hd/

Connect the enclosure to the Mac via USB.  Boot the Mac using the OPTION key.  Select the external hard drive icon.

If the Mac boots, then the internal connection is bad and should be replaced.

If the Mac does not boot, and the recovery partition is displayed, click on the recovery partition and select Disk Utility.  Run Disk Utility>First Aid, Verify and Repair.

If there is no hard drive icon or recovery partition, then the hard drive is bad and must be replaced.

Ciao.

You should also thank Google Translate. 

Good luck.

Ciao.