" My iPhone 6S Plus has boot failure, after it boots normally, the iPhone LCD screen displays abnormal, the iPhone LCD is half black and half bright, what should i do?" An iPhone user said it.
Disassemble the iPhone by phone opening tools, measure the boot current of the iPhone by DPS DC power supply, the boot current is larger than normal data, it's short-circuit. After 2 seconds, the iPhone suddenly back to normal, we think it's the current is too large and the damaged components are burned through.
The iPhone is turned on, but now the iPhone screen displays abnormal, it's half black and half bright.
Take out the iPhone motherboard, and then use digital multimeter to measure the fifth 5 PP_LCM_BL34_ANODE_CONN backlight anode of the J4200 display socket, it's short-circuit.
Tear off the black tape, and found that the light D4050 diode has
burned and ruptured, the resistance of the diode at both ends is 941 after
testing, so it is obviously damaged, we can observe it under the Trinocular Integrated Microscope.
Now we need to find out the short-circuit capacitance, and then replace the inductors, diode tupe and backlight power. Detecting the motherboard by rosin method, we found we found that the C4053 capacitor has obvious
discoloration. The L4050 inductor appeared tin ball because of large current
and high temperature, L4051 inductor is discolored and cracked. L4020 inductor also has crack marks.
Heating the C4050 via QUICK 861DW hot air rework station, and then use tweezers to remove it. Next we need to replace C4053, L4050, L4051, L4020, D4051, D4050.
After replacement, we need to measure the resistance of the two diodes by digital multimeter, now the data tested is normal.
Install the iPhone and test it, the iPhone is turning on smoothly, after entering the IOS system, the iPhone LCD screen works normally, and all functions works perfectly.
Comments
Post a Comment