Analysis & Solve: New photos can’t be saved on iPhone 6

 Why new photos can't be saved on my iPhone 6? A customers complained that. Now we need to check the iPhone, analysis the reasons and then solve this problem.

After checking,  the iPhone 6 fault is sometimes the photos can not be saved, but sometimes it's normal.  It is found that the iPhone camera can be saved now, so it's necessary to wait and observe again.

In the evening, we start disassembling to inspect what is the fault, the iPhone 6 motherboard has never been repaired, but the screw column is damaged, as shown in picture 12-1-1.

This screws column has a flashing light on the back of the camera. According to our repair experience, it is known that photos cannot be saved should be the iPhone flash IC problem. Will it be caused by screwd column? So after measuring the camera, the EN signal was found to be in a normal state, and would it be a semi - connected state?

After scraping, it is found that this line is nearly disconnected. Is it the problem here? The photo is really not saved after installing to test. Connect the line, the fault finally comes out.

Next, removing the flash IC off and cleaning the glue of the weld plate, then we start to measure the resistance, he E2 pin of the flash lamp is found to have no resistance. This is the I2C bus that connects the iPhone 6 CPU with the rear camera and the flash IC. The details are shown in WUXINJI schematic diagram.

Scraping the lead to get rid of the possibility of broken line.

The camera can get the resistance and get the exclusion of CPU false welding, it should be disconnected line problem in the plate. The solution is to connect jumper wire  from the E2 pin of the flash IC to the rear camera socket FL2329. After welding the jumper wire by QUICK 861DW rework station, the flashing light E2 has a resistance value.

Finally, install the iPhone and test it, now the iPhone 6 can store new photos.! 

DIY FIX: Backlight damage causes iPhone 6 won't boot

 Today, we will share a iPhone repair guide that how to DIY fix backlight damage causes iPhone 6 won't boot. When we supply power to iPhone 6 with C48 MFI USB Cable, the iPhone always shows black screen. Let's learn to diy fix it!

Connect iPhone to DC power supply, we find current 80mA circularly run while connecting and triggering, so maybe it's USB damgage cause I2C short circuit during charging process, first remove the iPhone 6 motherboard and take the USB off, but it's still the same as before, then we measure the I2C resistance and power supply! It is found that the I2C 0SCL is in a short circuit state. As shown in picture 11-10-1.

Since it's short circuit, it means the connected chip is damaged, the connected chips have display, backlight, main power supply USB and the iPhone 6 CPU.

First observe with VGA Camera 7-45X Trinocular Stereo Microscope, it is found that all the backlight diodes are burning and discoloring.

Then remove the backlight first, it does not short-circuit. The trigger current is normal, so continue to replace the 3 piece of iPhone backlight chips.

According to our past experience, if the large inductors gets discoloring, the large inductors with connected iPhone backlight IC would also have problems, so we replace them together. As shown in picture 11-10-2.

Measure it again with DC power supply, now the current is back to normal.  At last, instal the USB, and turn on iPhone, it runs smoothly and successfully. Keep going to check other functions, all is fine. The repairs end!

Troubleshoot: iPhone 6 Plus common touch issues

 As we know, the most easily damaged part of the iPhone 6 Plus is the touch. The iPhone 6 Plus touch  failure includes iPhone touch screen uncontrol,  screen hopping randomly,  zebra flicker on the top of the screen and so on.  Now, we troubleshoot it step by step.

First of all, replace a new screen to test, if the issues still exist, then we can start to detect the iPhone motherboard.

Test the ground resistance of the touch pin, which can intuitively let us find out where the problem is. At the same time, we can see that the 18 pin is the synchronous signal of CPU through the black touch M1 pin. If all these resistances are normal, voltage test should be started. By voltage test, we can more accurately judge which chip is damaged.

The voltage test must be buckled to the screen for voltage output, three power supply for black touch: +-5.7V shows power supply, and 1.8V shows it is given by power IC . As shown in picture 11-12-2.

Two power supply of white touch : 5.1V display power supply, 1.8V power supply IC. As shown in picture 11-12-3. It is possible to judge which IC is damaged according to the results measured.

The water damaged device shows that the power is easy to burn out so that 5.1V and white touch +-5.7V cannot be given. Broken device fault mostly shows on black touch, false welding is the most possible problem. During the soldering process, some technicians do not remove and redo but directly heat to the chip, customers can use them normally, but they will come back to repair after a while. It is better to take the chips off and replace the new ones.

The point of the black touch M1 pin is at the top of the plate layer, and it is easy to break the wire to cause the iPhone 6 Plus CPU signal to not be delivered, so we need to use the jumper wire to solve this problem. There is a point below the R2410, and the M1 pin is a circuit line, gently scraped with a blade under a magnifying glass, then get a little solder on the blade, blowing a small solder ball out with ESD hot air gun, it must be small, then welding the solder ball at that point scraped out with slow speed air gun, using a copper wire (can take off from solder wick) to fix on the scrape point and M1 pin, add the green oil and put under curing UV light. The process looks more complex, but the effect is very good, and it is basically no rework necessary.

In addition, take care not to damage the small components around the points, here are 2490, FL2486, C2439 three components,which are used for identifying the original screen, after you change the iPhone touch IC and install the original screen, if the screen is still not responsive but assembly screen can work, that is the problem. 

After installing the black touch IC, check whether the resistance of C1577 is normal, because it goes into IC, and it is surrounded by grounding pins. If the current is directly loaded onto 500mA on Fluke 15B+ Digital Multimeter, most of them are caused from here.

In the end, just be careful and be patient during the repair process!