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🛠 Difficulty: 🟢🟡⚪️
⏰️ Repair Time: 60 minutes
Today we received a Samsung S22 for repair with an unusual story: after being connected to a power bank for charging, the phone suddenly shut off and started emitting a burnt smell.
This is actually the first time we've encountered this issue—it’s hard to believe the phone got damaged just from charging via a power bank 🫢
The repair starts off as usual, with diagnostics beginning by disassembling the phone.
We heat and remove the back glass cover, unscrew the internal screws, and disconnect the battery.
We remove the motherboard and connect it to a lab power supply for testing.
On the power supply, we observe idle current draw of about 0.9A, and the board itself is noticeably heating up.
The heating is coming from the back side of the motherboard, toward the bottom area.
We carefully cut away a section of the metal shield and clearly see a burnt power management IC—MAX77705C.
This PMIC has been used in Samsung smartphones since the Galaxy S10 series, so you can find it on motherboards from models like:
Samsung G970 / G973 / G975 / G980 / G985 / G991 – Galaxy S10e / S10 / S10+ / S20 / S20+ / S21 / S21+ / S22 / S22+, etc.
Using a soldering station, we remove the burnt IC, prepare a replacement chip, and install it.
We then check the board's power draw and response to the power button. Everything looks good.
We place the motherboard back into the phone housing for testing.
The phone powers on and starts charging normally.
We also test fast charging, and everything works as expected. The phone is ready to be reassembled and returned to the customer 🙃
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