Solved: iPhone 6 No display with logic board repairing

We received an iPhone 6 need to be repaired, the problem is that the iPhone 6 has no display when it is turned on.

First check whether the iPhone display socket has water damaged or virtual welding problem, after removing these problems, measure the resistance value of the socket by digital multimeter.

After measurement, we found the display socket 12 pin doesn't have resistance value. Check if the connected c2001 capacitance and fl2034 inductance have corrosion and virtual solder problems, the fl2034 inductance measured are no resistance value.

The fl2034 inductance passes through the U2403 6 pin tube and then to the CPU. Using a digital multimeter to measure the iPhone touch screen control IC U2403 of the corresponding bottom pins, the data tested are normal. So, we can eliminate the CPU problem. In this case, we need to solder jump wire.

Use QUICK 861DW hot air rework station to remove the cover, and then solder a jumper wire from the 6th pin of u2403 to a measuring point next to the screw hole，and then solidify it with green UV oil.

Install the iPhone and test it, the failure has been solved.

How to repair iPhone 7 Plus vibration function unavailable issue

 The iPhone 7 Plus has some problem, it won't vibrate. How to repair it? Keep reading.

Disassemble the iPhone 7 Plus by phone opening tools, and then remove the iPhone logic board.

Check iPhone logic board under the Stereo Zoom Microscope, no obviously scars. 

Measure the iPhone logic board by multimeter, the data tested is normal,but the iPhone 7 Plus still won't vibrate.

Open the WUXINJI Dongle to check the iPhone schematic diagram, analysis the iPhone vibration IC working principle.

Frist,try to replac the iPhone vibration IC, after replacement, the iPhone 7P vibration function still is unavailable.  

Carefully check iPhone vibration IC working principle again, we found the M2800 is damaged. Use QUICK 861DW hot air rework station and Precision Titanium Alloy Tweezers to replace the M2800.

After replacement, install the iPhone 7P, get into IOS to test the iPhone, now the iPhone vibration fucntions works properly. The issue has been solved.

Hardware solution for iPhone 6 4013 error

A customer sent us an iPhone 6 to repair, the fault described is that the iPhone 6 reports 4013 error when flash it with iTunes. 

Frist, connect iPhone 6 to the computer with iPhone lightning cable, and then use iTunes to flash iPhone again, we found the white Apple logo appears properly but can't enter the normal mode and reports unknown error 4013.

The iPhone 6 reports 4013 error is usually caused by iPhone Nand flash or CPU problem. In this case, frist we need to remove the iPhone Nand flash, and then use iTunes to re-flash the iPhone, finding that the iPhone can enter the normal mode and report 40 error, seems it's the iPhone Nand flash problem.

The iPhone 6 reports unknown error 40 is normal thing when the iPhone Nand flash is not installed. Use JC Pro1000s Nand problem to read the data of the original iPhone Nand flash, and then write this data to the new iPhone Nand flash, but we found the data of the iPhone Nand flash couldn't be read.

 

Therefore, we can only use the iPhone IMEI to find the original iPhone Nand flash SN, BT and WIFI address. After find out this information, use iPhone Nand test fixture to write these data to the new iPhone Nand flash, and then install Nand flash to the iPhone logic board by QUICK 861DW hot air rework station.

Assemble the iPhone 6, re-flash the iPhone via iTunes, the flash process goes well. Activate iPhone and test it, all functions are working properly, the repairs end!

Repair Guide: iPhone 6 touch screen not working (no touch )

When touch the iPhone touch screen, it has no response, the iPhone 6 touch function failed to work.  Here is the repair guide.

Disassemble the iPhone 6 by phone opening tools, remove the iPhone motherboard, we found the iPhone black and white touch IC have been replaced by former repair man.

Measure the working condition for iPhone black and white touch IC, and measure the 5.1V and 1.8V of the iPhone white touch IC and the iPhone black touch IC +5.7V -5.7V and 1.8V power supply.

After measure them with digital multimeter, all the data tested is normal. Remove the iPhone black and white touch IC, and then measure the diode data for the solder pad, it is normal.

Based on previous repair experience, we know that the iPhone 6 Plus display socket synchronous signal inductance easy to empty weld and causes iPhone no touch at all. The data of iPhone 6 display socket synchronous signal measured is about 400 by digital multimeter, which is normal. According to this repair idea，we replace the new U2403 touch synchronous tube, and then turn on iPhone test it, but the problem still there.

Remove the touch synchronous tube, and then measure the 6 pin ground resistance, about 700, it is normal data. When measure the first pin, we found an anomaly, the resistance value of this pin is infinitely large，while the normal data should be about 400.

Check iPhone schematic diagram through the WUXINJI Dongle, we know that this pin is connected with a test point PP2405, the data of PP2405 tested is 400, which is normal, so we decided use QUICK 861DW hot air rework station to solder the jumper wire between PP24005 and the first pin on the synchronous tube .

Measure the iPhone motherboard again, the data tested is normal. Install the iPhone and test it, the iPhone touch screen has response when you touch it with your fingers, the touch function  back to work!

iPhone 7 Plus no service error – Fix iPhone baseband CPU

 When iPhone 7 Plus is turned on, but it can't make the phone calls, becasue the iPhone 7P has no service.  After check the iPhone, we found it is iPhone baseband CPU porblem, we can fix it. 

Check iPhone 7 Plus again,  dialing the *#06#, there are no IMEI appears on iPhone display screen. Check Settings on iPhone, there are IM and Modem Firmware numbers. After reset the iPhone network settings,  the problem still there.

Open the WUXINJI Dongle, and then compare with the iPhone schematic diagram and iPhone motherboard bitmap to measure the iPhone circuit line power supply. After measurement, all power supply on the iPhone baseband power tested are normal, we need to re-install the iPhone baseband CPU.

Because it is very close to main CPU, we need to do a heating insulation for the CPU. Use QUICK 861DW hot air rework station to heat iPhone CPU for a while, and then use BGA graver to gently remove the glue. We can remove the inductor on the right side fist and then insert the blade, or we can insert the blade in the slot，we'd better choose the thin blade. When heated it with hot air gun, we blow from the side of the CPU to the card slot. When we need to pay it, we can select a component around the baseband as a reference, and when the tin of reference begins to melt, we can start to pry into the baseband.

There are many empty on the iPhone baseband CPU, observe it under the Stereo Zoom Microscope, and then compare it with iPhone bitmap, there are many pins missing. Apply some lower temperature solder paste on the solder pad, and then soldering the iPhone baseband CPU with solder paste and glue, install it to the iPhone motherboard. After the iPhone motherboard is cooled, use digital multimeter to test whether the peripheral components short-circuit, so you can determine whether the chip has been installed intact.

Install the iPhone 7 Plus, turn on iPhone, now the signal is back, the service is normal.