Phone don't boot after screen replacement

Hey there,

I just change the screen of my phone, with a full ifixit replacement (front camera). After putting the phone back together, I tried to turn the phone on and nothing happens if is alone or connected to the PC. If I plug it to the charger the apple logo is showed, then went black with the back light lit. If I unplug the phone it shut down.

Tried to enter in DFU mode, but it only shows the logo for a few seconds.

Also tried to disconnect/reconnect the battery and seems that nothing change.

Any help will be appreciated.

Thanks in advance.