It could be a hardware issue, or a driver issue. It's much more likely that this is a hardware problem, though. The first thing he could try is clearing the "PRAM". Restart the Mac by holding Command, Option, P, and R.
He can also try booting from his system disc. If that works, then he'll know that his logic board is failing and that's an expensive repair. Hopefully Alex has AppleCare. Otherwise, it may be more worth it to just get a new Macbook.