iPhone XR stops working when playing games then keep rebooting.
Model: iPhone XR
Announced: 2018, September 12
Troubleshooting
The phone stops working when playing the game, then keeps rebooting. The defect is NOT caused by drop damage, water damage or improper charging, etc.
The phone can occasionally be into the system only… Tried many times, then enter it into the system.
There are many panic full reports, let’s randomly pick one to check
and we can see it reminds AppleSocHot. Hot Hot Hot…
The next moment the phone rebooted again.
For this kind of defect, we can only swap the encrypted chips to another board to solve the problem.
Repair Process
Let’s disassemble the phone and take out the motherboard
First, swap the CPU
- remove the shielding cover with the hot air gun, and clean the thermal grease
- remove the black glue around the CPU
- Heat with the hot air gun, then slightly insert the thin blade and keep heating until the CPU chip gets removed
Tips. be careful when heating the CPU, do not blow away the logic EEPROM (U1401)
4. Then clean the CPU, remove the black glue and resolder it
5. Then align the CPU to a new board and solder it back
Also, solder back the logic EEPROM.
After soldering back the CPU and logic EEPROM, we can connect the motherboard with the DC power supply, and trigger it to boot. The current jump to around 50mA, it’s a normal value and means the CPU is OK and well installed.
The rest steps
Swap the NAND chip and Baseband CPU to the new board
The detailed chip reballing and the resoldering process are not complex, just like what we shared in the Handwork Course.
Testing
After the swapping process, cool down the motherboard. Then assemble the phone to have a test. All the functions are OK, play video and play the game for half an hour no reboot issue happens again.
The issue gets resolved by swapping the encrypted chips (CPU, NAND, Logic EEPROM, Baseband CPU) to a new board.
