A customer sent an
iPad 5 to repair, the phenomenon of failure is that when press the iPad power
button, it has no response, the iPad touch screen is black. We need to disassemble it and check it.
The iPad display connector socket and the display line socket are damaged; also, there
is a marked scorch mark at the boost inductor. After measure the diode data of
iPad 5 socket, the boost inductor is the open circuit, the resistance of the
other side is normal. Replace it with new display connector socket and display
line socket, after installation, we found the inner display screen iPad backlight Diode can be lit, but
no display on iPad screen, so the initial judgment is that the iPad screen is
damaged.
Replace a new iPad
LCD screen and assemble it. Measure it with Fluke 15B+ Digital Multimeter, now the iPad
Tail plug detection signal has about 1.8V, and the screen can be lit after the
iPad power on. We thought the issue has been solved. However, when inserting an
Apple data cable to charge, the iPad percentage of battery charge has not
changed. We suspect that the initial failure of the iPad 5 is that iPad 5 battery charge fails,
power is missing, and then the iPad doesn't boot. Give it to someone else for
repairs, after replacing the screen, the issue still exists, and we found
several screws are not installed, the cover plate is missing and the wrong
installation of the screen socket causes a short circuit, now has more
failures.
Open the WUXINJI circuit diagram, and check the
charging circuits, the key signals of each road are basically normal. At this
time, we think Q8104 damage will lead to bad charging, so we directly use QUICK 861DW rework station to
short solder the jumper wire on Q8104. After that, activate iPad battery,
assemble the iPad, now the iPad can be recharged properly, other functions also
works perfectly.
Comments
Post a Comment