macbook hangs and displays a question mark
The laptop hangs and restarts. After reboot the folder with a question mark comes out. When you press cmd+R and check HDD writes that with it everything is normal. BUT! when you reinstall os, the hard disk is turned off. I reboot again and the hard drive works, but time passes and it is disconnected again. What to do? HDD then appears that shuts down. It happens that the system starts, but when it freezes again and again.
MacBook Pro, macOS High Sierra (10.13.1)