Phone touchscreen problem is the common phenomenon. The "touch disease" can make you headache. When come across this situation what should you do? Pls follow this article to check and fix your phone.
After turning on, the right display screen is black while the left normally displays, which is called Yin and Yang screen. When the right screen turns black, it still shows nothing after awakening it.
1. The abnormal backlight circuit could cause the Yin and Yang screen. First let’s start from the backlight circuit. After removing the motherboard, we find that the right backlight chip is painted green UV Solder Resist and soldered a jumper wire. The wire starts from pin A1 U1580 backlight chip to the yellow point near the fingerprint socket J2118, as shown in below picture.
2. The I2C bus that left backlight chip uses and the I2C bus that right backlight chip uses are not the same circuit. The left one is normal while the right one is not, even after the right backlight chip is replaced. Thus, we doubt that there is something wrong with I2C bus of the right backlight chip. The two backlight chips’ real material object are shown in below picture.
3. Observing the screw under microscope, we find that right and left screw holes are twisted through, as shown in below picture.
4. Use knife to scratch left screw hole, we find that it still connects. While the right one disconnects, as shown in below picture. Fixing the broken circuit and turn it on. Trouble is removed.