iPhone 5S battery draining fast after update to iOS 11. Now need to charge twice a day. How to know if it is really battery problem or board problem? don't want to change battery, only to know later it is logic board problem and vice versa.
Also, if repair outside, later when update iOS will get error 53 or not?
Phone around 4 years, so don't want to spend so much and end up not able to use.