The iPhone X has been dropped and can’t work normally. After restoring, the phone can’t be activated. REWA Lab technicians suspect that the motherboard was damaged after the phone was dropped. This article will share how we locate and eliminate the fault. Let’s check it out!
The phone fails to be activated after restoring. Next, we try to activate the phone with 3uTools.
Connect the phone to the computer and open 3uTools. Click Activate Now and Start. The activation normally takes several minutes. After about 20 minutes, the phone is stuck in the activation interface. The phone is still unable to be activated.
Then we disassemble the phone and take out the motherboard. Run a cosmetic inspection of the motherboard. The motherboard has no water damage and deform.
Next, we need to separate the motherboard for further check.
Motherboard Separation
Put the motherboard on the 165 °C Heating Platform to heat. When the temperature reaches 165 °C, remove the logic board and signal board with tweezers.
Clear thermal grease with a Sculpture Knife. After separation, it is found that there are many missing pads. Then we restore useful pads from missing pads with jumper wires.
Attach the logic board to the holder and remove tin on the bonding pad with Soldering Iron at 365 °C and Solder Wick. Apply some Solder Paste to the missing pads and apply tin with Hot Air Gun at 340 °C.
Clean the bonding pad with PCB Cleaner and apply some Paste Flux.
Making Jumper Wires
Solder 0.02 mm copper wires to the bonding pad with Soldering Iron. Please be noted that copper wires must be soldered firmly.
Clean with PCB Cleaner again and curl the copper wires to make pads with Tweezers and Sculpture Knife.
Apply Solder Mask to the bonding pad to fix the copper wires and solidify the solder mask with UV Lamp for 5 minutes.
Scrape away excess solder mask with Sculpture Knife to show the copper wires.
Next, remove tin on the bonding pad with Soldering Iron at 365 °C and Solder Wick. Clean the bonding pad with PCB Cleaner.
Reballing
Attach the signal board to the Reballing Platform and put the reballing stencil in position. To prevent solder paste from flowing into the motherboard, insert a metal plate. Apply evenly a layer of low-temperature Solder Paste.
Motherboard Recombination
Put the motherboard on the 165 °C Heating Platform to heat. After the solder balls are formed, turn the power off and cool the signal board. Apply some Paste Flux and align the logic board with the signal board.
Keep heating for 1 minute when the temperature reaches 165 °C.
Turn the power off and cool the motherboard.
Assemble and Test
Then we install the motherboard to the phone. Open 3uTools to activate the phone. The phone is successfully activated. Test other functions and other functions work well.
Watch the video below to see how we fix an iPhone X that can’t be activated.
