If it would work and get hot when screen is on - it would be screen cables for sure. But if it's even draining in idle I have few questions:
- was it even drop into water and you let it dry ?
- you changed SIM card lately?
- could you check charging port for any dust or rust ?
- you can go to Apple Store but imho it's something with motherboard or cpu itself - you will pay 100% because any changes you do to hardware is cancelling guarantee
I am not sure if its the screen cable, since it already started happening before I tear my phone down.
- No, it was completely dry and wasn't exposed to any liquid before the occurrence of the issue.
-I did change my SIM card, and sometime it appear "Invalid SIM" but it was only few moments that I had it. Is it an issue? I don't think it is the SIM card (still possible to be) since I always let it sit on airplane mode when testing.
-No rust, a bit of dust.
-I think the same, because it gets hot on the seemingly spot on the CPU -- few millimeters below the camera. I didn't know Apple would still repair my phone even though it was unauthorized disassembled. I would look at the warranty policy for more details.
[doublepost=1481387053][/doublepost]
https://news.ycombinator.com/item?id=13054056
It seems like I'm not the only one with this issue. Other users also reported their phones die at 30% but I have none of those except rapid drain during standby.