acer aspire 5742 series model pew71

Diagnosing a dead laptop without being "hands on" is very difficult.
My advice is take it to a repair centre and, if they'll agree to have a look at it, get an estimate for repairs as cost may make it too expensive to be worth it.

I know some one-off PC repair shops won't even look at a dead laptop, it has to show some signs of life.