[You must be registered and logged in to see this image.] Repair Tips and procedure:
1. check the mouthpiece microphone, replace if found damaged
2. check the microphone's terminal pads free from dirt and corrosion.
3. check the two filter coils, replace if found open or damaged.
4. check replace the capacitors near the power supply IC.
5. trace the line paths and if found open or cut, apply a tiniest magnetic jumper wire on it , its a recycling method but anyway it is very useful.
Note: It need expertise on this next procedures, if the solutions above does not solve the problem.
doing this process without related experience might end up killing the phone.
1. reflow or reheat the power IC using a Hot Air Gun, with proper controlled heat temperature.
2. remove the power IC, check each line paths indicated on the repair picture solution to each corresponding connected components.
3. Rework or reball the power IC's solder balls.
We personally tried and tested this solution and serve as our guide
for the following questions we search with.