Please i want really to solve this problem. Why the screen suddenly turn off and on also power switch and keyboard

If you're referring to the broken key on the keyboard (it's not clear), you'll need to replace the keyboard (more likely the palmrest assembly).

@ejn63​  no  i  am referring to  the screen of laptop suddenly turn off  and  on   also the keyboard with power switch    I don't know why it's happening   if you know anything please tell me. And many thanks