hi mohamed.rashad there is a two problem in you mobile i tink 1. ear speaker 2. front camera strip i tink mostly front camera strip problem there is a connectivity in speaker mostly that is problem pls replace that one it will work iPhone 6 Plus Front Facing Camera and Sensor Assembly Replacement
hi its pls check speaker connection is good or not by using multimeter... put optiom in beep mode and check the two point in two probes if its beep comes your speaker is working.... if its not working replace the new one and check 100% its works ear speaker
you can your but touch id function wont work why because your original touch id paired with cpu... if you put another touch id finger print not work so you not able to use touch id function you can use for menu button function
hi niannna 1st check the battery voltage minimum voltage is 3.6v if its not there change the battery or boot the your old battery and check..... 2nd check power flexi cable any damage 3rd connect to itunes its detecting or not in system if its detecting pls let me know
