It doesn't turn on and i can't open the hard reset menu and i only get the download mode it only shows me Samsung GALAXY...

I tried everything : if I was wrong way, if I used wrong screwdriver but non of those work

if you have on the battery saving mode or something like that it wont work turn it off and it might get fixed it should be in the notification panel. i think But if blue LED flashes i think its a technical problem

there should be an downloads in the app drawer

The only best that i recommend you to do is to take it to a mechanic/electrician