You may face motherboard line damage or missing soldering pads when repair your iPhone, in this article, we share how to fix iPhone 8 Plus no display by making jumper wires, hope you enjoy our sharing.
Step 1 Function Test
Buckle the iPhone 8 Plus motherboard with a screen assembly, connect to the DC Power Supply and boot up. The booting current showed unstable while going down and rebooting again, plus the screen has no display function.
The booting current measured stable, and when unbuckle the screen, the motherboard keeps rebooting.
Step 2 Diagnosis
Place the motherboard under the microscope and measure the diode resistance of the display connector. The diode resistance of the display connector pin 18 is measured open while the diode resistance of the pin 23 is measured too small.
Step 3 Troubleshoot
According to the schematic we can tell the open diode resistance is caused by fallen inductors. The diode resistance of the inductor solder balls is measured normal, next make jumper wires to repair.
Step 4 Repair
Add solder flux, add tin on the solder balls with soldering iron, connect the jumper wires to the solder balls, the diode resistance is remeasured normal, add UV solder mask and cure with the UV curing light.
The diode resistance of the display connector pin 23 still showed too small, when remove the capacitor C5604, the diode resistance measured normal, therefore, it’s the defect capacitor C5604 caused the too small diode resistance, repair by replacing a new good capacitor
Step 5 Reassemble and Test
Buckle the motherboard with a screen assembly, connect to the DC Power Supply and boot up, the iPhone boots up normally, the screen display works properly as well, repair completed.
Please refer to below detailed video:
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Tools and Materials Used in This Video:
DC Power Supply
Motherboard fixture holder
Solder flux paste
UV curable solder mask
UV curing light
Hot air gun
Desoldering braid/solder wick