Part of the buttons on the Acer 5755G does not work?

Question

Iron

This laptop has a keyboard with additional number buttons. So, at the beginning of the year, the north bridge was changed, I wrote about it here , literally a week ago I began to pay attention to the fact that the Fn key began to somehow not work stably, then it would work, then not. A couple of days ago, I noticed that the add. buttons (which are on the side) also partially stopped working - a list of faulty buttons: numbers 1, 2, 5, 6; when you press the number 8, “two” eights can be printed at once. PgUp stopped working. In general, there are problems with the clave. What can be the problem?
P.S. there are no crumbs and other food under the buttons, I didn’t fill it with beer!

Answer 1

There is a departure of the keyboard cable. Replug it and the problem should be gone.

Answer 2

Perhaps one of the tracks inside, going to them, is broken - practically unrepairable - replacing the keyboard (costs 1500r).