Issues of iPhone 6s 2g No Service and Vibration Function Issues
When the iPhone not have the buzz sound, you must do this. Before we begin, you check the iPhone vibration motor is turned on. You turned on the sound by flipping your iPhone Silent / Ring switch back and forth (the switch is above the volume buttons on the left side of your iPhone). If you don't feel your iPhone vibrate, it doesn't mean the vibration motor is broken, it means we need to take a look inside the Settings app. If the Setting app is right, maybe you need fix it. Now Vip Fix Shop Team will help you.
When we get the iPhone 6s, we find the iphone trouble phenomenon. It has some destroy the phenomenon that is fell into the water, but the signal was good, and it could't make the phone call, 2G signal showed no service, the vibration function couldn't be used.
So we start repair this problematic iPhone. Step 1. Power on iPhone, and test it, it has 3G and 4G signal, 2G signal is abnormal, it has no service. As shown in picture 1-1
Step 2. Disassemble the iPhone 6s, take out the motherboard, and then connect it to DC power supply, we found it leaking 13mA, the water cell phone 2g signal is not normal. To observe a passing element under a microscope, we found the R4501_RF resistance on 2G
PA U2GPA_RF has been moldy, as shown in picture 1-2. Touch it lightly with tweezers, it fell down. The PP_VCC_MAIN through it supply power to U2GPA_RF, so it caused the 2G signal to be abnormal. Clean it up and weld it with soldering station. After finish it, boot it and test it, the 2G signal is back to normal.
Step 3. The vibration function of iPhone 6s is controlled by U3800 PA chip. Use multimeter to measure the diode data of tail socket, the result is normal. After we remove the U3800 PA chip, we found the solder pad is moldy, so we replace the U3800 PA chip, after that, no leakage when the phone is standby and the vibration function back to normal. The repairs end! Picture 1-4