[Solution]How To Fix iPhone 8 Stuck on Apple Logo - GSM-Forum

Amanda0820 · 09-29-2018, 09:27

Once Touch ID gets malfunctioned, the phone gets stuck on Apple logo during startup and can’t continue past it to the home screen.

The solution ways as following:
1. Power on, Apple logo displays normally. Yet the phone gets stuck on Apple logo and can’t boot up completely.

2. Connect the phone to computer and restore via iTunes. Then insert the SIM card and activate the phone.

3. The Home Button gets unresponsive with returning function and the phone fails to activate completely.

4. Disassemble the phone and disconnect the battery. Then remove the display assembly.

5. 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.

6. Check whether the 3D flex cable of the display assembly is damaged or not. The 3D flex cable is in normal status.

7. 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.

8. Since Home Button is connected to the 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.

9. The phone still gets stuck on Apple logo and can’t boot up completely.

10. 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.

11. Take out the logic board and attach it to PCB Holder. Stick connectors next to J5800 with high-temperature adhesive tape.

12. Apply some BGA paste flux to the bonding pad and take down J5800 with Hot Air Gun at 320℃.

13. Then Solder tins with Soldering Iron. Which is helpful to the subsequent soldering process. Clean with PCB Cleaner afterward.

14. 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℃.

15. Wait for the logic board to cool for 5 minutes and then clean with PCB Cleaner. Check again to confirm soldering status.

16. 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.

17. Insert the SIM card and activate the phone. The Home Button gets responsive with returning function. Yet Touch ID failed.

18. 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.

19. Run function test. All going well. Fault cleared.

siewa26 · 08-24-2019, 12:45

Broken charging flex is often reason of apple logo bootloop - I had once iPhone 8 plus, possible to use lighting, updates via iTunes without problems , but after update - bootloop - enough to disconnect flex and phone booted normally

Yilia · 11-28-2019, 04:32

iPhone update, jailbreak, restoration, data transfer or even hardware issues and more may result in iPhone stuck on Apple logo. To let ourselves out of the trouble, we can try force restart, restore with iTunes (DFU/Recovery mode) or use UltFix iPhone System Recovery, to repair with no data loss. Sure, it will be much better if you have backups so that you don't have to worry about data loss.

09-29-2018, 09:27	#1 (permalink)
Amanda0820 Freak Poster Join Date: Aug 2018 Location: China Posts: 158 Member: 2861866 Status: Offline Thanks Meter: 71	[Solution]How To Fix iPhone 8 Stuck on Apple Logo Once Touch ID gets malfunctioned, the phone gets stuck on Apple logo during startup and can’t continue past it to the home screen. The solution ways as following: 1. Power on, Apple logo displays normally. Yet the phone gets stuck on Apple logo and can’t boot up completely. 2. Connect the phone to computer and restore via iTunes. Then insert the SIM card and activate the phone. 3. The Home Button gets unresponsive with returning function and the phone fails to activate completely. 4. Disassemble the phone and disconnect the battery. Then remove the display assembly. 5. 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. 6. Check whether the 3D flex cable of the display assembly is damaged or not. The 3D flex cable is in normal status. 7. 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. 8. Since Home Button is connected to the 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. 9. The phone still gets stuck on Apple logo and can’t boot up completely. 10. 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. 11. Take out the logic board and attach it to PCB Holder. Stick connectors next to J5800 with high-temperature adhesive tape. 12. Apply some BGA paste flux to the bonding pad and take down J5800 with Hot Air Gun at 320℃. 13. Then Solder tins with Soldering Iron. Which is helpful to the subsequent soldering process. Clean with PCB Cleaner afterward. 14. 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℃. 15. Wait for the logic board to cool for 5 minutes and then clean with PCB Cleaner. Check again to confirm soldering status. 16. 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. 17. Insert the SIM card and activate the phone. The Home Button gets responsive with returning function. Yet Touch ID failed. 18. 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. 19. Run function test. All going well. Fault cleared.

08-24-2019, 12:45	#2 (permalink)
siewa26 Freak Poster Join Date: Dec 2002 Age: 50 Posts: 135 Member: 19126 Status: Offline Thanks Meter: 35	Broken charging flex is often reason of apple logo bootloop - I had once iPhone 8 plus, possible to use lighting, updates via iTunes without problems , but after update - bootloop - enough to disconnect flex and phone booted normally

11-28-2019, 04:32	#3 (permalink)
Yilia Insane Poster Join Date: Jan 2018 Posts: 67 Member: 2797527 Status: Offline Thanks Meter: 4	iPhone update, jailbreak, restoration, data transfer or even hardware issues and more may result in iPhone stuck on Apple logo. To let ourselves out of the trouble, we can try force restart, restore with iTunes (DFU/Recovery mode) or use UltFix iPhone System Recovery, to repair with no data loss. Sure, it will be much better if you have backups so that you don't have to worry about data loss.