Use Professional Tools to Fix iPhone 6S Wake Up Failure

One of our customer sent his iPhone 6S to us, according to the attached file, we knew there happens display problems, but it can be turned on normally.

We disassembled it and found there miss some bottom screws, so there may happens some short circuit. And we knew it was repaired before, so have to pay more attention on this.

Considering this iPhone has a low chance of failure，so we start to repair from the simplest way, try to replace the iPhone display assembly. After replacement, test the iPhone for 2 days, it doesn't have any problems. However, after 2 days, test the iPhone again, the fault is back, seem the real problem is on the iPhone motherboard.

Take off the iPhone motherboard, put it under the Stereo Zoom Microscope to observe, we found the repair trace.

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Looks the previously repair shop also repaired this circuit, use digital multimeter to measure the resistance value of displace interface, the problem was found quickly.

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The data measured for 11 pin is 450, but the 9 pin is 390, it is obviously wrong. Measuring the other end of the conductor, the resistance is 390， until now we can confirm that the conductor is damaged or there is a virtual weld. Re-welding the conductor by using QUICK 861DW hot air rework station, and then measure the resistance for both pins, all is 390. Assemble the iPhone, and test it for few days, the iPhone 6S works properly, the problem of not waking up has been repaired!