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the iPhone 6 by phone opening tools, remove the iPhone motherboard, we found the iPhone black and white touch IC have been replaced by former repair man.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

Solved: iPhone 7 Plus compass abnormal issue

A customer sent us an iPhone 7 Plus need to be repaired, the problem is that the iPhone 7 Plus compass not working, it is abnormal. 

After we received the iPhone 7 Plus, get into IOS to test the iPhone compass function, it doesn't work.

Disassemble the iPhone 7 Plus by phone opening tools, take out the iPhone motherboard. The appearance of iPhone motherboard looks good, but there are traces of moldy around the gyroscope.

Carefully clean up the moldy areas, and then connect it to DC power supply, it boots normally. Install the iPhone, and test it, everything is fine, except the compass.

For this case, some people will think it's the compass problem, and it can be fixed by replacing the new compass; some people will think that the gyroscope is virtual welded, because the gyroscope is moldy, it can be fixed by reballing the gyroscope.

We need to observe the iPhone motherboard. Put it under the Stereo Zoom Microscope to observe the compass and gyroscope, the parts around the compass are good, but one of the 0 Ohm resistors around the gyroscope is slightly corroded, and two inductors ware also slightly corroded near the display socket.

Touch it with tweezers, it fell off easily. We need to short connect them. Use QUICK 861DW hot air rework station to solder the jump wire, and then clear it up.

Install the iPhone and test it, the compass functions works properly, the problem has been solved!

Guide: iPhone dead motherboard data recovery

Here is the guide for iPhone data recovery from iPhone dead motherboard. We got the iPhone 6 need to be repair, the problem is that the iPhone motherbaord is damaged, and the iPhone won't turn on anymore, but we need to recover the data from the dead iPhone motherboard. 

First, disassemble the iPhone by phone opening tools, and then take out the iPhone motherboard.



Desolder the A8 CPU, EEPROM and NAND Flash from motherboard with QUICK 861DW hot air gun.

Use rosin, BGA paste flux, PCB cleaner, soldering iron and razor blade to clean the 3 chips.

Reballing the chips with iPhone BGA reballing stencil.

Put the new motherboard on iPhone 6 PCB holder and remore the A8 CPU, NAND Flash, EEPROM from it.

Install the 3 chips removed from broken motherboard to the new one by QUICK 861DW hot air rework station.

Assemble the iPhone and check whether the data has been recovered.

Note: 

Please handle these 3 chips very carefully to keep them safe.