iPhone XS Max Camera Portrait Mode/Depth Effect Not Working Repair

Open the camera app and swipe to portrait mode. We can see clearly that the background is not blurred.

Which indicates that the wide-angle lens is working normally, while the telephoto lens is not working at all.

Run diode mode measurement of the Tele camera connector J4000. The measured value of Pin 25 is OL, which is abnormal.

The first thing we do is to check the zero-ohm resistor R4006 on Pin 25 relevant circuit. Nothing goes wrong.

We can confirm that the fault is probably related to U3700, the camera power supply IC on the circuit.

Let's try to replace with a new IC.

Place the motherboard on the Heating Platform, which can quickly desolder&resolder iPhone XS Max double-layer motherboard.

Pick up the upper layer with tweezers once solder on the third space PCB has melted.

Detach U3700 from the board with Hot Air Gun.

Clean the bonding pad and then solder a new IC.

Next thing we do is to solder the two layers together.

Clean the third space PCB with rosin soaked Solder Wick first. Then reball the lower layer.

Get the upper layer and the lower layer in position. Power on the Heating Platform.

Several minutes later, power off and wait for the motherboard to cool for 5 minutes.

Open the camera app and swipe to Portrait Mode. We can see that the subject is being focused and the background is blurred.