Chosen Solution

My iPhone 6 was dropped into water and as such I had to replace the battery, screen with home button and charging/headphone port. I thought it was fine however now getting strange behaviour. The battery charges ok and phone starts up on charge, when cable is removed all is ok, can shut down phone using power button, however cannot start phone back up. Additionally phone will often ‘die’ and again can’t be restarted until plugged in. While on charge, phone dies and restarts often. Battery charges fine and reads good percentage. Things I’m thinking;

  1. bad battery
  2. damaged battery terminal (can’t see anything obvious)
  3. unseated battery connector (have rechecked)
  4. bad power button (although turns off fine)
  5. short somewhere
  6. software problem
  7. power ic Dont know really where to start..! anyone had similar issue?

Sounds like a board level issue. You may want to have a microsolderer look at your phone’s internals to determine if a component is busted. My advice is that you bring your phone to a microsolderer and ask for an analysis there. If you don’t have any microsolderers nearby it may just be best if you replaced the Logic board altogether.