Why does my iPhone won't turn on?

So I drop my iphone and my display stoped showing any image (it went all black but it had light) so I figure out that maybe a connector from de display got disconnected in the fall. I opened my phone to see if something got disconnected but when I disconnected the battery I think I may or may not have induced a short circuit in the battery terminal (I disconnected it with a screwdriver so the positive and negative made contact). The battery inmediatly got discharged, but I let it charging for a while and now is back to normal, but the Iphone just won't turn on at all. Someone told me that it was because when a short circuit happens in an iphone sometimes it blocks and you have to change an integrated circuit in the mother board. Is it true? Or is there another way I can fix it?

PLASE HELP ME :(

Ps: Sorry for my English haha it's not my first language