Got the same default :
iPhone Touch Screen can't display while the screen shows good and motherboard can work normally.
The first step we do still is to check the motherboard to get the current and current, it shows normally, so we have to check other's part.
Fix Process:
First use DC power supply to measure the boot current on iPhone, the boot current is normal. Tilt the iPhone screen, we can see the Apple LOGO, which means the iPhone 6 is not no display but without the backlight.
Remove the iPhone motherboard and measure the resistance of display socket backlight circuit and backlight power supply by Fluke 15B+ Digital Multimeter, we found the data of backlight power supply only has 97, but the normal data is more than 400.
Picture 14-12-1
Take off the iPhone CPU shield to check the components near the backlight. After check it under the VGA Camera 7-45X Trinocular Stereo Microscope, it was found that the backlight diode had been burnt, and the big inductance also is cracked and discolored. In this case, the elements on the back light path should all be damaged, we need to remove all components and replace the new.
Picture 14-12-2
After replacement, turn on iPhone to test, now the iPhone screen displays normally, the repairs end!
Picture 14-12-3
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