My MacBook Pro 9,2 suddenly cannot boot anymore (I see a question mark). I started it in recovery mode and disk utility does not seem to see any HDD plugged in. I removed the HDD and I placed it inside a USB adapter, and it seems to be properly recognized by another Linux machine. Then I tried to boot the mac recovery system and the HDD is properly recognized from the same USB case. Then I tried to install a SSD unit inside the macbook: recovery system can recognize the SSD properly. Any idea why the macbook seems to suddenly be unable to detect a regular old original HDD when installed with the SATA connector while still being able to detect SATA SSD and to detect anything plugged via USB? I also tried to reset NVRAM and PRAM, nothing changed.