My laptop's screen is blank after switching it off

I was working on Kali Linux installed in virtual box in my laptop ( which has windows 10 OS).

While working, suddenly screen got black or dark blue screen. No key was working on it, so I switched off my laptop. After that the trouble begins.

1.
On battery, my laptop is on but there is no sound of fan running (it is actually not
running ) and only blank screen I can see.

2.
When I try to switch off my laptop, it switches on by itself.

3.
I removed the battery, then plugged in my charger. My laptop switched on without pressing the power key.

Please can someone tell what has happened to it? And how can I fix that?