Last week, we received the customer's iPhone 7. He said that he accidentally dropped his iPhone into the bathtub, even though he immediately picked it up. But his iPhone won't boot. After receiving the iPhone, we started to fix the work. Here are our repair steps.

First, we use the Fluke Digital Multimeter to detect current and voltage and do not trigger a 900mmA machine leak. The reason for the failure is still uncertain. With the help of the QUICK 861DW hot air rework station, we successfully removed the iphone 7 motherboard. After careful observation, it was found that the capacitor c2307 was broken.

To make matters worse, when we observed the motherboard with 180X stereo zoom microscope, we found that the two large audios under the capacitor were corroded. Capacitor c2307 falls into the water part for cleaning. After power-on, it finds that the leakage is 100mA, and the machine can trigger the boot normally.

Test the machine without vibration or sound after turned on iphone. The doubt is that we have not found this problem before. Both audio amplifications are removed. Measuring the secondary body value found that the u3402 A2 is 30, and the normal is more than 300. The problem may come from here. And the A2 pin is connected to only M2800.

It seems very likely that the M2800 was damaged, so we need to replace the M2800.

After replacing the chip, measure whether the U3402 A2 pin resistance is normal, but the repair work is not finished, because we need to remove the damaged audio IC with tweezers and then switch to the new iphone audio ic. After the power is turned on, the test machine no longer leaks, triggering a normal start. The sound vibration also returned to normal. The fault was solved and the repair work was successfully completed.

After reading this article, have you learned to fix this fault? If you have any questions, please visit www.vipprogrammer.com.