lenovo 330s-15ikb, led num lock key always on and numbers don't work

[resistor83]

hello everyone, I have a particular problem with this lenovo ideapad 330s-15ikb. I had to replace the motherboard due to liquid damage, after replacing it I noticed that some letters on the keyboard do not work. So I bought a new keyboard and now all the keys work except the numeric keypad area. In practice the num lock key LED always remains on and the numbers do not work. Has anything like this ever happened to you? I also tried changing the keyboard again but the same defect remains on the numeric keypad.

I tried updating the bios but the problem remains

https://streamable.com/c8sj3h (here video)

[mon2]

Review the keyboard scan lines as they mate to the EC. The EC is the keyboard scanner with its internal 8051 / ARM processor.

[m1ch43lzm]

Maybe you got a motherboard for the 14" version without numeric keypad?
https://www.badcaps.net/forum/troubl...4ikb-schematic

Check post #14 for the schematics and silkscreen (no proper boardview, but it'll do)

Compare the values of RI13, RI20, RI21, RI25 on both old and new boards, you may need to modify the new board to match

[resistor83]

here are the measurements between the broken motherboard and the new one, I can see (photo) that between the two motherboards the resistors are positioned differently:


MOTHERBOARD BROKEN ORIGINAL:

RI21 80,6K

RI13 18,6K

RI25 66,7K

RI20 9,8K





MOTHERBOARD NEW WORKING:

RI21 78,5K

RI13 66,3K

RI25 65,3K

RI20 186,3K

[m1ch43lzm]

The modification should be, according to your pictures
1. Remove RI13
2. Install a 10k resistor at RI20, you can take it from the dead board

You can use a soldering iron to remove RI13, otherwise you risk damaging the plastic connector below with hot air

As i said, You got a board for the 14" model (330s-14IKB) as they look identical on the outside

[resistor83]

it works!! thanks!!