The author is repairing a Lenovo IdeaPad Gaming 3-15ACH6, a 2021 model equipped with a Ryzen 5 5600H processor, an RTX 3050 Ti GPU, and 16 GB of DDR4-3200 RAM. The device was purchased in a non-functional state with signs of liquid damage.
Initial diagnostics showed the motherboard consumed almost no power from a laboratory power supply, and input MOSFETs remained closed. Thermal imaging revealed two overheating chips: the Silergy SY8388BRHC (PU301) and the ENE KB9022QD (UEC1) system controller.
The author determined that the ENE KB9022QD controller had an internal short circuit, causing the 3.3V LDO line to drop to 20 ohms. Removing the faulty controller restored the resistance to over 13 kOhms and allowed the PU301 converter to function correctly.
The repair process requires replacing the ENE KB9022QD chip and programming it using a Mic-Vision (SAS I/O Programmer) version 4.1. The author is currently waiting for the delivery of the new component to complete the final soldering and firmware installation.
