re: PS4 won't boot up. Anybody else had this problem?

I've had this issue after a power failure improperly turned the console off while in use. Just had to do a hard boot and it rebuilt it's database on startup.

No idea what to do if yours isn't doing that.

Might be worth it to make sure the hard drive is still seated correctly. Could also be an old hard drive failing. If that's the case Sony made them really easy to replace.

Good luck.