Apple.
inc Introduction
Diagram ZXW/JcId
EEPRom
USB/U2/Trister- ic code
1610A1-A2-A3 iphone 5s iphone 7 plus
1612A1-A2-A3 iphone 8 iphone 11 series
1614A1-A2-A3 iphone 12 series
1616A1-A2-A3 iphone 13 series
Iphone maximum information stored in CPU/Rom.Its called mac address
Vbatt>VCC.Vph>VDD,VDD boost
Shorted scquences
Half shorted :
1 amp plus current rom's capacitors
powered phn auto amp , 2G pa ,Wifi, Ringer ics,U2(Usb ic),charging ic,
logic
iphone temperature too high-wirless charging flex/dock,wifi ic
1st boot current high(100 mA)>U2 ic faulty
Full shroted:
Check if the vcc or vdd shorted
If VCC shorted>remove capacitors(big)near by battery connector
If VDD shorted use testpoints or use high current among vdd related capacitors
Hang on logo:
1.Proximity sensor
2.Flashing(on turning blackscreen)
3.Rom(reformatting)
4.Ram(reheating)(reballing)
5.Rearcamera Flashlight flex
6.If the phone is dropped,re-attach the rom's terminals
7.Water damaged