iPhone 5S backlight brightness is failed to be adjusted normally

If anything happens to your cell phone, what will you do? Maybe it will affect your life,work and study. So you had to prepare the broken phone. The common problem of  phone is touch screen. Now vipprog will introduce you some tools to fix your phone problem.

Problem:

The iPhone has been dropped into water and the auto-brightness works normally, but backlight brightness function is abnormal when I adjust it by myself. The specific situations are that 20% brightness display reaches min brightness while 0% brightness display reaches brighter brightness.

Repair:

1. Backlight circuit often causes this kind of problem. Checking the working condition of backlight chip, we find that capacitor C131 looses. The circuit diagram and material object of capacitor C131 is shown in below picture.

2. Use multimeter to touch capacitor C131 and it drops. At the same time, the power supply solder pad under capacitor C131 drops too. After checking the bitmap, we find that the diode D1 that is connected to capacitor C131 is just next to it, as shown in below picture.

3. Solder a wire from the negative pole of diode D1 to the positive pole of capacitor C131, as shown in below picture.

Turn on iPhone again and adjust the backlight brightness. The function can be used normally now.