Flashlight not working after screen replacement

So, a friend brought me his iPhone 5s because he knows I like to play with this kind of stuff.

His phone had the screen shattered. So, I ordered a new one, and tried to follow the instructions but I had a few problems during the repair.

1st, There was four connectors under the bracket, 3 of them came from the display (I think they were, digitizer, camera and earpiece and lcd) and one that I dont know.

The one that I don't know where it comes from was accidentally disconnected with my prytool and I had a hardtime trying to get it into place.

I finally got it into place and could turn the phone on. Screen ok, digitizer ok, touch id ok, front camera ok, earpiece, proximity sensor, everything seemed ok.

1 day later he called me. His volume button is not working properly, he cant raise the volume, only lower. And the flashlight is also not working.

I must admit I forgot to test the flashlight, but the volume rocker I did, and it was working just fine.

What should I do now?