CAMERA ERROR: iPhone 6S Plus liquid intrusion then rear camera not working

As the saying goes, the knife cuts bread and fingers. Water is the essential thing of human body, but not your cell phone, you must keep your cell phone far away from the liquid, and otherwise, it will damage your cell phone. There are many examples, today we are going to talk about the iPhone 6S Plus camera issue after liquid damaged.

Problem description

The iPhone 6S Plus accidently drop into water, and then it has no backlight, when fix it, the front camera is normal, however, the rear camera is not. The 2.8V chip is replaced.

Solution

1. Disassemble the iPhone with phone opening tools, we found that some components near the camera socket J3200 are eroded. After checking the circuit diagram, we find that three inductors are missing. The three inductors in bitmap are shown in yellow points in picture 1 and material objects are shown in picture 2.

 

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2. Directly short connect the two ends of the inductor to speed up. After the whole iPhone is fixed, we find other workable inductor to assemble. After short connecting the two ends of the inductor, use multimeter to measure the diode data to ground of its socket, the data is normal. We think it recovers now. So we assemble camera and energize it to test. The problem is still the same. Remove the camera and energize motherboardto measure its voltage. First, we measure whether I2C bus has 1.8V voltage as well as the 1.8V and 1.2V voltage that rear camera need. The teat points are shown in yellow parts in picture3.

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3. The above voltages are normal. We measure a special voltage 2.85V, the pin 16 in picture 4. After assembling rear camera and turn on iPhone to open rear camera, this voltage will appear. We cannot measure it because the flex cable is connected, so we doing jump wire to measure it.

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4. After measuring, we find no 2.85V voltage. The later series of iPhone 6S, the front 2.85V voltage is output by power chip while the rear 2.85V voltage is made by LDO reduction voltage chip U3200. The circuits of LDO chip are shown in picture 5.

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The U3200 in bitmap is shown in picture 6. 

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5. Observe camera under the microscope, picture 7 ,it has no apparent corrosive behavior. Measure the working condition of VIN and EN, which are normal.  Besides, it has replaced U3200 before, we suspect that U2300 was replaced with a bad, so we replace the new U2300.

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Finally, we assemble the rear camera, and test the front/rear camera, all is normal. This iPhone 6S Plus was been repair, and it can back to normal work.

Note:

The front and rear cameras of iPhone 6 and iPhone 6 Plus use the same 2.85V voltage. If 2.85V voltage has problems, both front and rear cameras cannot be used.