Lenovo Ideapad 120S - 11IAP Unknown chip heating!

[martin1555]

Hey Guys,

I bought some broken Laptops from an Amazon Liquidation seller and now I am trying to fix as much as possible.

They where pretty cheap so failing ist not an drama

Tools I own: Hot Air Gun
Soldering Station Daytools LS-937
USB-Microscope

So acutually I should be ready to do all possible solder work.

As I put some Voltage on the told Mainboard, I first used the USB-C port. Which showed no reaction at all. No charging light and no warming components.

Then I saw, that it has an DC IN Port with "normal" connector. On the bottom of the Laptop it says DC IN 20V. Because I dont wanted to search the right adapter, I started with an 12V one. Which maybe was an smart idea.

As soon as I plugged the charger, some SMD-Chip was starting to heat up very quickly. I added some alcohol to the PCB and it was the only part which does this. No other component is even warming up.

No charging-light with this connector too.

I made an screenshot with my microscope.

unfortunaly I found NOTHING at all about the shown Codes. (ALVJ 222)

Do you maybe have an idea what chip is could be? Or an schematic for this board maybe?
I would realy happy about some hints here...


Thank you in Advance

[qayyum786]

Re: Lenovo Ideapad 120S - 11IAP Unknown chip heating!

here you go
U2000 (NB680GD) IC belongs to 3.3v:

[martin1555]

Re: Lenovo Ideapad 120S - 11IAP Unknown chip heating!

so thanks to your schematic I did a lot of measuring and it turned out, the be a faulty IO CHIP. The complete 3.3V rail is shorted.

As I removed the ENE KB9028Q all shorts where gone. Directly at the Chip where multiple short (about 6ohms) between VCC 3.3 and GND.

So I will order a new one, and lets see if it comes back to life

[sanjiv16]

Re: Lenovo Ideapad 120S - 11IAP Unknown chip heating!

i have same model turn on but no display,but it display in the monitor.i already tried good screen ang good lcd flex but still black,how can check the mothernoard related to display