No camera and fingerprint on Iphone 6 Plus—how to fix?

The iPhone 6 Plus fingerprint function, rear and front camera all unavailable. Customer described that he repaired the iPhone black touch IC, it is possible to put the back of the component virtual weld. Anyway, we need to fix it step by step.

 

 First of all, measure the diode data of rear camera adapter with Fluke 15B+ Digital Multimeter, no exceptions found. Then measure the rear camera power supply.

Measure the main camera 1.8V and 1.2V power supply, when we measured the 2.85V power supply, we found that it had no power. Check the iPhone 6 Plus schematic diagram on WUXINJI Dongle to trace the 2.85V source.

We found that the 2.85V was converted from the main power supply through U2301. During the repair process, short connection A1 and A2 pin can quickly determine if 2.85V power is causing the iPhone camera not working. After short connect A1 and A2 pin, get into IOS to test the iPhone rear camera, it can be turned on now, but short connect 2.85V conversion tube can only test whether it is caused by 2.85V. We can't stop the repairs, because the voltage of PP_VCC_MAIN is 4V, but the power supply of this circuit is 2.85V.

Direct short connection, take pictures in the darkness, sometimes there are white stripes, you not only can replace the conversion tube here, but also can weld jump wire from the iPhone Nand flash 3V. Generally we weld the jump wire from iPhone Nand flash 3V power supply.

After finished the welded jump wire, we start to repair fingerprint. First measure the diode data of fingerprint socket. When measured the 12th pin AP_TO_MESA_SPI_MOSI_CONN, its resistance is infinitely large. Trace AP_TO_MESA_SPI_MOSI_CONN signal, we found that it was renamed directly by AP_TOMESA_SPI_MOSI through inductance fl2132. Since there are components in the middle, then we just check FL2132 under the 7-45X 180X Stereo Zoom Microscope.

Gently wave the components with Precision Titanium Alloy Tweezers, we found it had fallen off. According to iPhone circuit diagram, we know that this inductance is an insurance inductor; the insurance inductor can short-circuit the two pins directly together. When finished, assemble iPhone and test, fingerprints are fine now, the repairs end!

Best Solution--iPhone 6 camera get stuck when turn it on

A customer sent an iPhone 6 to us to repair, the fault described is that the iPhone 6 rear camera sometimes won't turn on, and there is a vertical bar when take photos. According the repair experience, first we measure the diode data of rear camera with Fluke 15B+ Digital Multimeter.

When we measure the diode data for the 34th pin, we found it unstable. Sometimes more than 300, sometimes more than 500 (The normal resistance is about 500). Open WUXINJI Dongle to check iPhone PCB schematic diagram, we know that this pin is 2.85 power supply pin.

This 2.85 power supply pin is converted from U2301.

Base on the above conclusions, we suspect that this could be caused by a 2.85V conversion tube virtual weld.  Gently shake the conversion tube with Precision Titanium Alloy Tweezers; The conversion tube has fallen off. We can check it under the VGA Camera 7-45X TrinocularStereo Microscope

Now, replace a new conversion tube. And then turn on iPhone to test, now, when you turn on the camera, it won't get stuck. The iPhone rear camera can be turned on smoothly.

iTunes error 4014 on iPhone 6S—How to fix?

The customer sent us an iPhone 6s needs to be repaired, the fault described is that it reports unknown error 4014 when flash it. After detecting, the current is 57mA, DFU mode, flashing it and it reports 4014, which is consistent with customer description.

Disassemble it to check the iPhone motherboard, the iPhone Nand flash on this motherboard has been repaired, and when check it under the microscope, we can see that the iPhone NAND flash damaged.

Remove the iPhone Nand flash and measure its diode data, it is normal. Put Nand flash into the WL PCIE Nand test programmer to test it, unsurprisingly, the NAND flash is damaged.

Replace the new iPhone Nand flash and flash it again, the fault still exists. As we know, the iPhone 6S and later iPhone reports iTunes error 4014 mostly caused by nand flash and baseband issues. However, after measuring, we know that the iPhone Nand flash is good, so now the problem is iPhone baseband. Measure the diode data of baseband power LDO part and S1-S5 power supply, all is normal.

Flash it again, test the S2 and S4 when the White Apple logo appears, there is no power in either of these places. Since S2 and S4 have no power, it is possible that the baseband power supply does not work and then can't output power. Remove the baseband power, and then use Fluke 15B+ Digital Multimeter to measure it, we found the 55 pin is to ground.

55 Pin connected to the 19.2M clock, put iPhone motherboard under the VGA Camera 7-45X Trinocular Stereo Microscope to observe the 19.2M clock.

19.2M clock with C3501_RF capacitor grounding end connected together

Handle the baseband clock well, and then flash it again, now the progress bar can run normally, and iTunes doesn't report unknown error 4014 anymore.

Here! Get solution for iPad Air 2 touch function unavailable issue

 Received an iPad Air 2 to repair, its problem is the iPad Air 2 screen completely unavailable after water damaged. It was sent it to repair once, but not working. You can get solution here!

After receiving the device, we can see both of the two white touches were damaged seriously. The iPad boost diode, black touch and electric tube had changed, and the touch screen was completely deformed. This white touch is the least damaged, so we replace the 2 serious damaged white touch first. This white touch is general with iPhone 6 white touch IC, so we replace it to test on iPad, the failure is still existing. Most of technicians must know that AIR2's black touch is a common trouble, so we begin to measure whether the black touch has a boost.

The voltage is only 2.3V on the C4014 when measured with Fluke 15B+ digital multimer, and there should be a main power supply even if the voltage is not boosted. Measuring the inductor L4001 we find that the voltage was different. Taking off the inductor to test, it is the original inductance was burned.

Replacing the inductor L4001, check the diode D4001 is not damaged, continue to test the device and find that there is still no boost out, this place should have a boost even if no LCD installed. The inductor diodes are checked in the three large parts of the boost, only the black touch itself does not work will cause no boost. The last repairman has changed the black touch, now we can only change the black touch first. After changing the black touch, it is still the same as not to boost. so we can continue to check the working conditions of the black touch, opening WUXINJI Dongle to check.

Both black touch power supply have value: 5.25V and 1.8V  .

The power supply of the 12C bus is normal.

It is found that the black touch EN signal comes from the white touch U4150. Is it the replaced white touch problem? Before replacing the U4150 touch, first checking the U4150 and find there is something lost, after checking diagram, we get to know it is the resistance U4154.

Through the original factory diagram, it can be found that the R4154 is the touch clock frequency pull-down resistor. According to the usual maintenance idea, it is learned that one end of the chip is grounded, and the pull-down resistor must not drop, similar to the REXT resistance in iPhone.

A resistance of 4.7K was found on the iPhone motherboard, and boot to test there is boosted out, and 18-20V. 

Finally, install the iPad screen to test, now the iPad Air 2 touch function is back to normal,  you can touch it randomly, it works perfectly!