2019 latest Solution for iPhone 8 Stuck On Apple Logo problem

A customer sent us an iPhone 8 need to be repaired, the fault described is that the iPhone 8 can't enter the IOS system, it just stuck on Apple logo after powering. Here is the latest solution to fix it.

Before we are going to fix it, we need to prepare some phone fix tools.

- Phone opening tools

- Microscope

- digital multimeter

- QUICK 861DW

- PCB holder fixture

- BGA solder paste

- Others

Now, let's start to repair.

Turn on iPhone 8, Apple logo displays normally, but the iPhone gets stuck on Apple logo and can’t boot up completely. Connect the phone to computer and restore through iTunes. Then insert the SIM card and activate the phone.

The Home Button gets unresponsive with returning function and the phone fails to activate completely. Disassemble the phone with iPhone opening tool kit 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 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 PCB Cleaner after logic board to cool for 5 minutes. Check again to confirm soldering status. Next, assemble logic board and connect the battery. Power on, the phone can access to the activating interface normally.

Now, insert the SIM card, and then step by step to activate the iPhone, it worked. Finally, all functions tested on iPhone is fine, the repairs end!