Q: Black Macbook Won't Start

It's hard to tell what's happening with this machine, since time and wear are considerations. I don't know what version of the OS you're using, but there's a sequence of things you should do - in order of severity.

http://www.howtogeek.com/217158/what-to-do-when-your-mac-won’t-start-up/

There is a problem with the battery connection. (Or it`s just the age)

Unless your up for winging it, or if you have apple care(maybe). Your out of luck.

Because it would cost about $150 to fix it.

I have a Macbook early '09 and this just started to happen. It wasn't rebooting and when it did I had a double vision and/or split screen(half of it was black).  You can buy a used one for $200 on Ebay so time to bid it good night at my end.