Lenovo IdeaPad 3 15IAU7 that suffered water damage

[Joel Ohana]

Hi,

I have a Lenovo IdeaPad 3 15IAU7 that suffered water damage. It doesn't turn on (white power light flashes when on button pressed), and the amber light flashes when plugged in.

Symptoms:

• Short detected – sparks appear when touching the charging port connection with board with a metal (even a multimeter probe).
• Visible damage – after cleaning corrosion, I found 4 possibly burnt memory chips near PC3165, labeled UD5, UD6, UD7, and UD8.

What are my next steps to diagnose and possibly repair it without replacing the entire board? Any guidance would be greatly appreciated!

Thanks,
Joel

[FriedFred]

First, pull-out the battery connector, memory, SSDs and WLAN modules.
Second, make some good photographs of the TOP and BOTTOM side of the board. Especially those areas, which appear to be not normal anymore.
Third, make a good, thorough clean-up of all areas in question.
Fourth, measure the current consumption in stand-by. It must be around 10mA in stand-by.
Is a dead-short before the two input MOSFETs? Or is a dead-short at any other coil?

[Joel Ohana]

Thank you for your answer!
I removed all the modules. I attached photos of the board.
What I circled in red looks burnt, and sparks are detected from it when the charger is connected and that part is touched with a metal.
circled in yellow are parts I suspect have burnt signs.
How should I measure the current consumption in standby? connect the board to the charger, and measure what with the multimeter?
(sorry about the newb questions...)

[FriedFred]

Photo A: The power supply Connector itself is burned.
Photo B: This capacitor is suspicious! Test it for short!
Photo C: No idea, what this can be.

You shall use a separate power supply with current adjustment! Adjust the shorted current to 200mA and power the board. The current consumption you can read from your power supply. Or you measure the voltage drop over the current measuring resistor and calculate the standby-current.