Generally, for these common iPhone problems, we can try some software solution first, if software solutions are not working, then we should check iPhone hardware aspect.
1. Reboot iPhone 7
In order to reboot iPhone, please press and hold iPhone power button until the slider appears, and then drag the slider to turn the iPhone 7 completely off, after the device turns off, press and hold the iPhone power button again until you see the Apple logo.
After powering, test the iPhone front camera, it's still not working.
2. DFU restore iPhone 7
Before we DFU restore iPhone 7, we need to backup the iPhone first, so we won't lose any data. Connect the iPhone 7 to the computer via iPhone lightning cable, backup the iPhone 7, and then put iPhone 7 in DFU mode, finally use iTunes to restore the iPhone 7.
After restoring, power on iPhone 7 and test the iPhone front camera, it still doesn't work. Next we need to check iPhone hardware problem.
3. Replace the new iPhone front camera
Is the iPhone front camera damaged by water? We try to fix by replacing the new iPhone front camera.
Use qianli 2D screwdriver to remove the two screws on the bottom edge of the iPhone, put iPhone 7 on the CPB screen separator to soften the adhesive securing the display, so we can open it more easily. Use OP Plus Screen Sucker to open the iPhone, but not completely separate the display. Now we need to take off the lower connector bracket, and disconnect those connectors that connected to the iPhone logic board, so that we can remove the iPhone display assembly, finally we can disassemble the iPhone front camera and sensor cable.
Now, install the new and good quality iPhone 7 front camera, and then assemble the iPhone 7. Power on the iPhone 7, test the iPhone front camera, unfortunately, the iPhone 7 front camera still not working. Next we need to check iPhone motherboard.
4. Repair iPhone motherboard
Now, we need to disassemble the iPhone 7 to check the motherboard. After disassembling the iPhone, take off the iPhone motherboard, we found that the area of water had corroded and blackened.
Put iPhone motherboard under the Trinocular Microscope, we can see it clearly that the iPhone front camera 1.8V power supply insurance inductor FL2901 and right corner of the camera socket had blackened.
Clean it up, apply some solder paste to it, and then use QUICK 861DW hot air rework station to solder it. After soldering, assemble the iPhone 7.
5. Test the iPhone 7
Now, power on iPhone 7, open the camera App to test, now the iPhone front camera works properly, and all other functions tested are normal.
Your iPhone front camera should be working by now. If you come across other problems about your iPhone, let us know by posting your comment. If you find the article is helpful, share it with your friends.