My iPhone 6s Plus doesn´t turn on even after a battery replacement
recently I bought two iPhone 6s Plus from someone privatly. He told me that the phone on question recently had a battery replacement done by a repair shop. A couple of days later it died and smelt “weird”.
Problem is: I thought it was a problem with the charging port/ battery. I replaced both with working parts but it won´t turn on, isn´t being recognized by the Computer (not even in DFU-Mode or by any other software. I contacted the costumer service because the battery was still under warranty by the manufacturer (Hagnaven a company that at least to my knowledge seems to be very good). Only thing that I wonder about is: Why does a repairshop use an almost TWO year battery to replace a battery of costumer? I don´t know if I can hope for help from the manufacturer of the battery.
Right now what I am wondering:
What are the possible defects? (I already replaced every part EXCEPT for the Mainboards of course. :D)
How much will I have to pay in parts/ repair-service?
Is it a problem where I need a SMD-Station for? If so: do you have recommendations for a cheap but OK station?
If you have any questions about something ask.
Thanks in advance.