SAMSUNG S9 Plus No Wi-Fi Issue Repair
Model: S9+
Announced: 2018, February 25
Defect Phenomenon
Wi-Fi cannot be activated.
When the phone gets received, it’s obvious that the screen has been replaced, and the phone was drop damaged before.
Repair Process
Try to connect with the Wi-Fi to test, it reminds is connecting to the Wi-Fi but tried a long time still cannot be connected.
Since the phone was drop damaged, preliminarily judge the issue is caused by the Wi-Fi chip poor soldering or damage.
Remove the Wi-Fi chip with a hot air gun and sculpture knife.
As the middle of the Wi-fi chip with small components, only the surrounding with pads.
Please pay special attention when inserting the knife to pry up the chip, do not insert it into the chip too deep to avoid scratching or damaging the inner part of the Wi-Fi chip.
Reball the chip, then solder it back to the motherboard to have a test. But the issue remains the same.
Is that possible the Wi-Fi chip has been damaged? Since there’s no schematic, let’s just try to replace the Wi-Fi chip with a new one. After replacement, the issue is still unresolved.
OK, calm down to carefully check the motherboard under the microscope again.
Everything looks fine~ Is that possible there’s something wrong under the shielding cover?
The components under the shielding cover as below
There is a big inductor under the shielding cover, which should be relative to the power supply for the Wi-Fi module.
And once we removed the shielding cover, as we can see the inductor is a little bit poor soldering. Push it with the tweezer slightly it just comes off directly.
Then apply some rosin and tin paste to deal with the pads on the PCB first, after that, solder back the inductor with a new one. Assemble the phone to test, the Wi-Fi function back to normal.
The issue gets resolved by resoldering the inductor under the shielding cover.
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