How To Fix iPhone XR Rear Camera Not Working Faulty

Basic Fix Ideas On Motherboard

The rear camera faulty fix of the iPhone 8 and its successors is easier than its previous iPhones. Because since the iPhone 8, all iPhones apply multi-pin integrated chips instead of power supply connectors with 4 pins. Generally speaking, for iPhone 8, and the following iPhones, there are mainly two causes for the rear camera not working faulty on the motherboard:

  1. I2C bus

Flashlight and rear camera share the same I2C bus. Under such circumstances, when one part has been damaged or not working or the I2C bus itself has been faulty, it will cause the other parts not working. Therefore, when flashlight has been faulty, it will lead to rear camera fail to work, vice versa.

  1. Camera Connector

There is an interrupt signal on the camera connector. The signal is connected to the CPU and the camera cannot work without it, so the camera connector also needs to be checked:corrosive power supply parts, pseudo-soldering chips, or broken circuits connected to CPU.

That being so, we can fix an iPhone rear camera faulty according to its performance. Such as, if the rear camera cannot work, and the flashlight work normally, then it is the CPU signal faulty instead of the I2C bus.

Case Study: Fix An iPhone XR Rear Camera Not Working

Now we will give a demonstration of an iPhone XR and you will learn the fix methods and steps.

Step 1: Check The Performance

First of all, let’s check its performance. It is quite easy, just check the flashlight. It turns out the flashlight is normal, so it is the camera connector faulty if the rear camera itself is OK.

Step 2: Replace Rear Camera

Before moving to the motherboard fix, we still need to check the rear camera. After all, replacing a rear camera is much easier than fixing the parts on the camera connector.

Hence we disconnect the screen ( How? Please check here: iPhone XR screen replacement guide), remove the battery connector, and take down the rear camera. Then install a new rear camera. After that, we test again, however, the rear camera still won’t work, so it is indeed the camera connector faulty.

Step 3: Measure Camera Connector

Two steps for measuring camera connector:

  1. Measure the diode readings of the pins on the rear camera connector, if the values are abnormal, we then check the related circuits. However, all the values are normal, so we move to the next step.

  1. Measure the voltage of the connector. Check out the circuit diagram: the related parts include pin2, pin10, pin12, pin14, pin20, pin26. Hence we only need to test these pins. It is not easy since all the power supply voltages of the rear camera are instantaneous values except for 1.8V camera power supply, so we need to test many times to find out the truth. After a series of testing, it turns out that the pin20 has no voltage.

Step 4: Analyze The Abnormal Voltage

Check out the circuit diagram: pin26 and pin20 have the same voltage 2.85V, so we connect their circuits to make pin20 function again. Check again, the pin26 is connected to C3909, while pin20 is connected to C3994. Here comes the solution, we could jump a copper line from C3909 to C3994 to fix the pin20.

Step 5: Jump Copper Line

Now let’s jump copper line to connect C3909 to C3994, do it as follows:

  • Take down the motherboard and fix it on a PCB holder
  • Heat up C3909 to C3994 to remove the adhesive so that they can be connected

  • Apply solder flux and melt the solder wire on C3909 with a soldering iron, so that it can be coated with tin

  • Next, weld a copper wire on C3909

  • Then melt the solder wire on C3994 for tin coating and weld the other side of copper wire on it

It is not easy, better to have an advanced welding tool: hot air gun desoldering station.

Now the pin20 no voltage issue has been fixed, the rear camera not working issue should have been fixed. We install the phone and test again. Needless to say, the phone rear camera works perfectly.

You can find the detailed demonstration here:

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