iPhone 8 Plus No Service Solutions after Dropping / Logic Board Repair
We have received an “No Service” iPhone 8 Plus from our customer. After booting up and testing, it is ruled out that it is an iPhone account problem, so we guess that the problem is related to the phone's hardware, which may be caused by the baseband disconnection. We will disassemble the iPhone 8 Plus to check the iPhone logic board.

As we know, the problems caused by dropping for the iPhone, there are two main reasons, one is the iPhone solder pad drops pins, and the other hand is the iPhone is short-circuited.

Use 3D screwdrivers to remove the screws next to the iPhone lightning port, and then use screen sucker to open the iPhone display screen. Remove the iPhone display screen, disconnect the iPhone battery, and then take off the iPhone motherboard.

Put iPhone motherboard under a microscope to observe, we can see that this iPhone 8 Plus has been repaired, the DSM_LB_E and DSM_HB_E these two chips on the motherboard has been removed.

Log in to ZXW dongle to check iPhone 8P schematic diagram and bitmap, and use digital multimeter to measure the resistance value for the iPhone IC solder pad, we found SCLK_HB_LB_DSM_FILT_E signal of the DSM_LB_E and DSM_HB_E chips are shorted.

Check iPhone 8P schematic diagram and bitmap, we found the resistor R1608_E is in the position of the C1602-E capacitor, the location of the C1602-E capacitor on the schematic diagram is not installed.

Use hot air gun and tweezers to remove the resistor in the position of the C1602-E capacitor, and install it to the right position, solder the jumper wire to those pin that were dropped, and then install the IC to the motherboard.

Now install the iPhone 8P and test it, but the problem is still the same, the iPhone 8P still no service.

Disassemble the iPhone 8P again, observing it under the 7-45X Black Microscope, compare it with the iPhone schematic diagram, we found that the FL1501-E inductor was missing.

Use hot air gun and tweezers to install the FL1501-E inductor to the motherboard, and then assemble the iPhone 8 Plus.

Finally, turn on the iPhone 8 Plus, insert the SIM card, the signal is back, the iPhone 8 Plus got the service.

Hope the above method is useful to you. If you have other maintenance ways, please leave us a message in comment.

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