The customer sent us a faulty iPhone8, and the Apple logo is displayed normally. However, the iPhone card is not fully activated on the Apple logo. The following is a repair tutorial provided by our phonefix shop team.

First, connect your phone to your computer and recover from iTunes. Then insert the SIM card and activate your phone. On return, the Home button is not responding and the phone cannot be fully activated. Use the iPhone Opening toolKit to remove the phone and disconnect the battery. Then remove the display assembly.

Use digital multimeter to measure the power supply voltage of Home Button. The measured voltage value is 3.3V, 1.8V and 2.75V. Normal voltage value for the three are normal. Then, remove the Home button and check if the iPhone fingerprint flex cable (FIX235) is damaged, in fact it is in a normal state.

To further confirm the fault point, we replace with a new display assembly. Get the Home Button mounted on the new display assembly. Buckle the new display assembly to the iPhone logic motherboard. Then power on.

The phone still stuck on Apple logo and can’t boot up. Remove the display assembly, switch to diode mode and test the resistance between J5800 pins and grounding. Under the Stereo Zoom microscope, there are obvious repairing marks on J5800 . So we can replace connector J5800.

Take out the logic board and attach it to PCB Holder. Wrap with high-temperature adhesive tape. Apply some BGA paste flux to pad and take down J5800 with hot air gun at 320℃.

Clean with a PCB cleaner after cooling the logic board for 5 minutes. Check again to confirm the welding status. Next, assemble the logic board and connect the battery. After booting, the phone can access the activation interface normally.

Insert the SIM card and activate the phone. Take out the SIM card after the activating process. Finally, run function test, all going well, fault cleared.

If you want to learn more mobile phone repair guides,please visit www.vipprogrammer.com.