Have you been this situation that is your iPhone won't turn on. Sometimes you may think that you should buy a new one because it is obsolete. That could be true if the problem is bad enough, but there are some ways to try to fix your iPhone before deciding it's dead. If your iPhone won't turn on, you can follow this guide to try.
IPhone 6S cannot be turned on after dropping. The material object is shown in below picture.
1. Connect motherboard to DC power and it shows no current. The motherboard has no marks of short circuit. Short connect the power on pin and it shows high current, which suggests that there is short circuit on some voltage of open circuit.
2. Measure the diode data of each power supply on the motherboard and find the diode data of PP_CPU voltage is 0.002. Obviously it is too small, as shown in below picture.
3. As many components are connected to PP_CPU voltage, it will take a long time to exclude one by one. So we put rosin on the surface of each component evenly. Short connect power on pin and find the rosin on capacitor C2006 beside CPU melts fastest. The material object is shown in below picture and the relevant circuit diagram of C2006 is shown in below picture.
4. Remove capacitor C2006 directly and measure the diode data of PP_CPU voltage. Now the data becomes normal. After connecting display screen, this iPhone can be turned on normally. Trouble is removed.