Different from previous versions, there is a built-in hardware detection for iPhone 8 with
booting process. Once Touch ID gets malfunctioned, the phone gets stuck on Apple logo
during startup and can’t continue past it to the home screen. What’s more, the rest of the
iPhone features become inaccessible. Traditional solutions for iPhone stuck on Apple logo
issue can be various. Since there is no one-size-fits-all solution to this problem. But for
iPhone 8 stuck on Apple logo problem caused by Touch ID? The situation can be much
more complicated. In this article, REWA LAB will show exactly how to fix the iPhone 8
stuck on Apple logo problem with a completely new solution.
iPhone 8 Stuck on Apple Logo FIX
Power on, Apple logo displays normally. Yet the phone gets stuck on Apple logo and can’t boot up completely.
Connect the phone to computer and restore via 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 and disconnect the battery. Then remove the display assembly.
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 sets of voltage.
Check whether the 3D flex cable of the display assembly is damaged or not. The 3D flex cable is in normal status.
Detach the Home Button and check whether the home button flex cable is damaged or not. The home button flex cable is in normal status.
Since Home Button is connected to logic board with flex cable on the display assembly, to further confirm the fault point, replace with a new display assembly. Get the Home Button mounted on the new display assembly. Buckle the new display assembly to the logic board. Then power on.
The phone still gets stuck on Apple logo and can’t boot up completely.
Preliminary judgement – Home button malfunction resulted in iPhone 8 stuck on Apple logo issue.
Remove the display assembly. Switch to diode mode and measure the resistance between J5800 pins and grounding. Normal resistance value. There are obvious repairing marks on J5800 under the microscope. So we can have the connector J5800 replaced for a try.
Take out the logic board and attach it to PCB Holder. Stick connectors next to J5800 with high temperature adhesive tape.
Apply some BGA paste flux to the bonding pad and take down J5800 with Hot Air Gun at 320℃.
Then Solder tins with Soldering Iron. Which is helpful to the subsequent soldering process. Clean with PCB Cleaner afterwards.
Apply some BGA paste flux to the bonding pad. Align the new connector to the right place. Then solder the new connector with Hot Air Gun at 320℃.
Wait for the logic board to cool for 5 minutes and then clean with PCB Cleaner. Check again to confirm soldering status.
Get the logic board assembled and connect the battery. Buckle the display assembly and power on. The phone gets access to the activating interface normally.
Insert the SIM card and activate the phone. The Home Button gets responsive with returning function. Yet Touch ID failed.
So we need to restore again via iTunes. Once finished, activate the phone again. Touch ID back to normal this time.
With a carrier lock built into the phone, take out the SIM card after the activating process. Only in this way can we move to subsequent function test.
Run function test. All going well. Fault cleared.
For more details on iPhone 8 Stuck on Apple Logo repair, please go to REWA YouTube channel.