Screen unresponsive even after replacement

Before a drop, the screen was unresponsive occasionally.

Before the screen replacement it sill worked, and reacted. However, it got hot (more or less under the place where the lcd connectors are), when Internet was in use.

Then another drop followed, with the screen to be permanently unresponsive.

After the screen replacement with a new one (bought from this site, i.e. an OEM one) it remained further unresponsive, i.e. I cannot unlock it, although the screen locker screen is displayed in normal quality.

I tried reconnecting the cables, made e soft-reset (pressing Home+Power button for 10sec) and still no reaction.

Now, if the screen is ok, and the cables seem to be well connected, what else could be the problem ?