iPhone 6s Cannot Make Phone Calls

Share:

Defect Phenomenon

An iPhone 6s with water damage, and when connected with 4G network  the iPhone 6s cannot make phone calls normally.

Troubleshooting

Normally, when we make phone call with 4G network connected, there should be 4G signal bar displayed on the screen. But this phone displayed nothing on the signal bar.

Since it’s a water damaged phone, so we should check the water damaged part first. And based on the repair experience, making phone call failure with a high chance is caused by the 2G amplifier IC () get damaged.

iPhone 6s cannot make phone calls

Repair Process

First, let’s disassemble the phone, and we find the cooling paste sticker is gone. Obviously this phone has been disassmbled or even been repaired before.

Besides that, we can see the small components around the shielding cover is dirty and with corrosive signs. So just tearing down the shielding cover on the signal related chips, and go for the 2G amplifier IC directly.

Remove the chip and measuring the diode values on the PCB pads.  

2G PA Chip

After measuring, there is no diode value on the pin 8. The pin is the power supply pin for the 2G Power Amplifier IC, normally, the diode value should be around 300!

So there must be some components which related to the pin 8 with problem. Check the bitmap and schematics

iPhone 6s Cannot Make Phone Calls

R4501

It’s related with R4501_RF, C4501_RF, C4503_RF. The three components.

And among them, the resistor get corrosived very seriously. We can remove it with tweezer slightly.

456

So go for it! Replace the R4501_RF with a new one. Then measure the diode value on the pin 8 again, it’s back to normal.

Then solder back a new 2G PA IC, assemble the phone, and make phone calls to test again.

Phone call function back to normally.

Cannot make phone calls issue get resolved by the resistor replacement.

Summary

The water drop damaged phones are not as difficult as the drop damaged phones.

We can always start from checking the cosmetic carefully and deal with the abnormal components. Maybe the serioud issue can be resolved by a small operation!

Share:

REWA Academy

As an enthusiastic educator and expert in mobile technology, REWA Academy has dedicated its career to empowering individuals through technical education. With a keen focus on cellphone repairs, they have developed comprehensive online and offline courses at REWA Academy. Their expertise spans a wide array of areas, including iPhone repair training, phone hardware, software, and advanced troubleshooting techniques. Through their writings, they aim to demystify mobile technology complexities, making it accessible and understandable for both novices and professionals in the field.

Advanced Phone Repair Course

Do you aspire to become a professional in the phone repair industry? If so, visit REWA Academy to learn in-depth phone repair from industry experts.

Leave a Reply

Your email address will not be published. Required fields are marked *

RELATED Articles

How to Fix the iPhone 12 Pro Max Touch Not Working

How to Fix the iPhone 12 Pro Max Touch Not Working

When your phone’s screen becomes unresponsive, the usual solution is to replace it. However, screens are quite expensive these days. In this article, we will introduce an alternative method of...

Samsung A53 Won’t Turn On Repair

The Samsung A53 model is widely recognized as one of the most desirable smartphones currently available. However, like all electronic devices, it is susceptible to occasional operational issues that may prove...

Use the Vivo T1 In the Rain and Won’t Turn On

The client uses the Vivo T1 in the rain and won’t turn on after that. Let’s see the detailed troubleshooting and fixing process. Model: Vivo T1 Announced: 2021, October 20 Defect...