How to solve your iPhone 6S won't turn on problem_Logic Board Repair

Follow this guide to fix the problems of iPhone 6S won't turn on. This guide offers you a very detailed logic board repair solution of the problems which iPhone 6S won't turn on after falling. If you want to learn more about iPhone logic board repairing guide, follow the more comprehensive version that covered most of the iPhone model visit HERE.

Failure Phenomenon

The iPhone 6S cannot power on after falling. As shown in Pic 1-1.

How to solve your iPhone 6S won't turn on problem_Logic Board Repair

iPhone 6S after falling Pic 1-1

Maintenance Procedures:

After connecting the motherboard with the DC power supply, no current was shown and there was no obvious short circuit on the motherboard itself. It was found that the current is a bit large after short connecting the boot pin, which indicated that there was the short circuit of a voltage on this iPhone’s booting circuit. Measuring the ground impedance values of each major power supply on the motherboard by multimeter, it was found that the ground impedance values of the voltage PP_CPU are 0.002, which is obviously too small. As shown in Pic 1-2.

How to solve your iPhone 6S won't turn on problem_Logic Board Repair

Short circuit of the voltage PP_CPU Pic 1-2

Since there were so many components connecting with PP_CPU voltage, it was a time-consuming job to eliminate them one by one. So we chose to use fumigation method that is to dip the soldering iron into the rosin then evenly spread them on the surface of each component. After starting up with short connecting the booting pin, we noticed that the rosin on the surface of the C2006 melted faster. The C2006 is on the edge of CPU. The position of the C2006 capacitor on the motherboard is shown as Pic 1-3. The circuit of the C2006 is shown in Pic 1-4.

How to solve your iPhone 6S won't turn on problem_Logic Board Repair

The position of the C2006 capacitor on the motherboard Pic 1-3

How to solve your iPhone 6S won't turn on problem_Logic Board Repair

The circuit of the C2006 Pic 2-1-4

After directly removing the C2006 capacitor, we measured the ground impedance values of the voltage PP_CPU again and it was back to normal. The iPhone could turn on as normal after connecting the screen. The problem solved. As shown in the Pic 1-5.

How to solve your iPhone 6S won't turn on problem_Logic Board Repair


The iPhone could turn on as normal after connecting the screen Pic1-5









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