For phone heavy users, fast charging is essential for everyday use. Because of the phone hardware upgrades, more and more apps consume more battery life. If the fast charging is not working, it must be repaired as soon as possible.
There are two kinds of phone fast charging: high-voltage-small-current and low-voltage-large -current. Samsung employs high-voltage-small-current fast charging. Thanks to the NOTE 7 charging incident, the Samsung S10 series employ 15W for the sake of safety. It takes more than 100 minutes for full charging. If the fast charging not working, it will cost more time.
Here we will share a Samsung S10e fast charging not working faulty.
Testing And Faulty Analysis
We use a Samsung AFC charger to charge the phone and observe the charging power. As a result, the value is only 0.7W or so, obviously, the fast charging has not been enabled.
We need to test the phone and find out what has been faulty.
- Firstly, take down the phone, so that we can test the parts inside.
- Then, check the USB-C connector, and no PCB gold fingers corrosion and broken connection.
- Lastly, we check the charging IC. Fix the motherboard and fix it on the PCB holder, and heat up the charging IC cover shield at 380℃, wind power 40, and take it down. After the motherboard cooling off, install the phone, connect the battery. Then plug in the fast charging cable and measure the charging IC voltage, as a result, the value is the only 4V, while the normal value should be 5V~9V.
Charging IC Replacement
Since the boost capacitor and inductor are normal, hence we conclude that the charging IC has been faulty. We need to replace it, do it in the following steps:
- Take down the motherboard and fix it on the PCB holder
- Apply soldering flux on the charging IC and take it down
- We need a new charging IC, however, we have no Samsung S10e charging IC in hand. Fortunately, we have a Samsung S8 spare motherboard. Since the charging ICs from Samsung S7 to S10e are the same, so we take down its charging IC in the same way as the original charging IC
- Then trim the S10e motherboard welding spots with the soldering iron
- Remove the remaining soldering flux
- Check the bonding pad, make sure that it has been clean and smooth
- BGA the charging IC from S8 spare motherboard
- Apply soldering flux, and align the IC with the bonding pad according to the polarity
- Set temperature to 360℃, wind power 30, and heat it up for 15 seconds
- Touch the small parts around the IC gently with tweezers, if spring-back, then the welding is OK.
After motherboard cooling off, we install the phone and test the charging voltage, the charging power is 9.4V, 1.2A, close to 12W. Everything is coming up roses, we boot up the phone and check the charge it, and the system indicates that fast charging is working, problem solved.
Please check the detailed operations here: