Power and mute not working - probably water damage

Today I received iPhone 5s from customer with power and mute not working. When I disassembled I see that both papers are red and metal motherboard bracket under LCD connectors was desoldered and soldered by someone. Volume + and - are working.

I tried to replace power/mute/volume flex but without success. I think that it can be IC on motherboard. Is there someone who know which chip is responsible for that?