Diven Lux cellphone review and repair guide

iPhone rear camera can not be activated? Give rear camera replacing a try and it doesn’t work this time? Well, you’d better start with logic board solution now. With this iPhone 6 camera not working case analysis, REWA LAB demonstrates a high-level logic board repair technique that can definitely surprise you.

iPhone 6 Camera Not Working Case Analysis

Tap “Camera” icon and enter into camera mode, the rear camera cannot be activated. Switch to front camera. It works normally.

Let’s replace with a new rear camera at the beginning. Disassemble the phone, detach battery and then remove the display assembly. Take down the rear camera and replace with a new rear camera.

Get the display assembly buckled and connect the battery. Then power on and test. The rear camera still cannot be activated.

Remove the display assembly and take down the rear camera. Measure the rear camera power supply voltage. The power supply voltage value is normal.

Then, measure the resistance between rear camera connector and grounding. The resistance value of pin 30 is 303, which is abnormal. The reference resistance value of pin 30 should be 537 or so.

Pin 30 works as the activating signal of the flashlight. It is also connected with pin E3 of flashlight IC U1602 via FL2322 and C2300.

Take down the logic board. Then attach the logic board to PCB Holder. Then take down capacitor C2300 with Hot Air Gun at 320℃. Then measure the resistance between pin 30 and grounding again. The resistance value of pin 30 is 300, which is abnormal.

Then we can draw the conclusion that IC U1602 broke down.

Take off the shield plate of CPU with Hot Air Gun at 320℃. We can see that the flashlight IC is right next to CPU, and to protect the CPU from high temperature when removing IC, we need to cover the CPU with the detached shield plate.

Blow with Hot Air Gun at 320℃ and pry off the flashlight IC with sculpture knife. After that, clean tins on the bonding pad with Soldering Iron. Then clean again with PCB Cleaner.

Once the logic board is cooling enough, measure the resistance between pin 30 and grounding again. The resistance value of pin 30 is 0, which is normal.

Apply some BGA Paste Flux to the bonding pad and align the new flashlight IC to the right place. Remember to cover the CPU with the detached shield plate. Then solder the new flashlight IC with Hot Air Gun at 320℃.

Once soldering is finished, wait for the logic board to cool for 5 minutes. Then measure the resistance between pin 30 and grounding again. The resistance value of pin 30 is 518, which is normal. Which also indicates that the fault has been cleared.

Get the logic board assembled and connect the battery. Buckle the display assembly and power on. The rear camera can be activated this time. Rear camera fault repair finished.

Does this guide useful? And you can also read our iPhone 6 won’t turn on and S7 edge glass replacement fix guide.

https://blog.rewatechnology.com/how-to-fix-iphone-6-camera-not-working-problem/

Some users complained about the iPhone frozen issue of their iPhone 7 after dropped. Even reinstallation couldn’t help with the iPhone frozen problem once and for all. REWA  LAB worked on the iPhone frozen issue and found out that the malfunction was caused by the iPhone7 producing process and could be solved by the maintenance of audio circuits. REWA LAB offers a new iPhone frozen solution regarding logic board repair!

Fix The iPhone Frozen Screen Issue With Logic board Repair Solution

Power on, the screen is stuck off and power button responses slowly.

Disassemble the phone, detach the display assembly. Replace with a new display assembly.

Turn on the phone and test. The screen is still stuck off.

Enter into record mode, the record icon is in nonfunction state. Screen replacing doesn’t help on the stuck issue, we can tell that there is a problem with the audio circuit. Move on to logic board repairing.

Take out the logic board and tear off the shield sticker.

Apply some BGA paste flux around the audio IC and blow it with hot air gun at 300 degrees. Then take down the audio IC.

Dip some rosin with soldering iron to clean the tins. Then dip some rosin with Goot wick for secondary cleaning. After that, clean again with PCB cleaner.

Test resistance value of pin C12 (U3101 audio IC). The resistance value is swinging.

Roll out the maintenance drawing for reference. Locate the signal of pin C12: 12S-AP-TO-CODEC-MCLK. The signal was connected with CPU via resistor R1103.

Scrape the insulation varnish off the copper wire connecting pin C12 and resistor R1103. Solder tins and then solder the 0.02mm copper wire.

Apply some UV curable solder mast to the soldered copper wire and put the logic board under the UV dryer lamp for 15 minutes.

Reball the audio IC with BGA reballing stencil.

Apply some BGA paste flux to the bonding pad. Then align the audio IC to the right place and blow it with a hot air gun at 280 degrees.

Once the logic board is cooling enough, clean it with PCB cleaner.

Assemble the phone and test.

Touch function and record function back to normal.

https://blog.rewatechnology.com/fix-iphone-frozen-screen-issue/

What should you do if your iPhone 7 won’t turn on after being dropped? The problem may be caused by a software crash or a complicated hardware issue. We have published an iPhone 6 won’t turn on guide video, and this time, we received an dropped iPhone 7 Plus which cannot turn on. The problem was finally detected as CPU being short-circuited. Here we have detailed troubleshooting procedures.

iPhone 7 won’t turn on

Diagnosis

Take apart the phone and disconnect the battery, then connect the phone with the DC Power Supply and press the power button to power on. The current reading of the ammeter jumps to 350mA and then stays still, which is abnormal and indicates that the logic board is short-circuited.

disassemble the phone and detach the battery

Disconnect the power supply and take out the logic board. Run diode measurements on capacitors around power IC one by one. All the values are normal except  C1823 – It displays 0, which indicates that C1823 is short-circuited. From the schematics, we can see that C1823 is the filter capacitor of PP1V8-SDRAM, and it is directly connected to CPU SDRAM.

diode measurements on capacitors around power IC

Repair

Attach the logic board to the PCB Holder, and take down the shielding cover by heating with Hot Air Gun, then remove CPU SDRAM with CNC Chip Grinding Machine. After chip grinding, attach the logic board to the PCB Holder and clean it with PCB Cleaner, then remove the black adhesive around with Sculpture Knife. After that, apply some BGA Paste Flux to the bonding pad. Align the new SDRAM to the right place(Don’t reverse the direction),  and then solder with Hot Air Gun. After cooling for 5 minutes, clean thoroughly with PCB Cleaner.

CPU SDRAM chip grinding

Testing

Connect the phone with the DC Power Supply, then short Pin 13 of J4504 to the ground with the tweezer to trigger the power on the system. This time, the current reading on the ammeter is normal.

connect the phone with the DC Power Supply

Get the logic board assembled and buckle the display assembly. Connect the phone to the computer, then press and hold volume down and power button to get into DFU mode. Restore the phone via iTunes. Once done, insert the SIM card and activate the phone. After testing, All the functions work normally.