Black screen, power and battery are ok

Hi,

Check fuse in plug first...!

Take the battery out and then plug the power adapter in and try to power it on, if it comes on power the laptop off again remove power adapter and put the battery back in and plug the power adapter back in.
If it didn't power on or light up on the laptop then the power adapter has gone faulty, buy a new one.

Power it on again, if it doesn't power up at all and there are no power lights the battery has come to end of its life.

If it powers on fine, then it just locked up, one of those things.

Thanks