820-3476 row of key not working even with new keyboard

[ajdoc]

Cant find any liquid.
Tested with three keyboards and on external systems.
Keys 3, e, d, c are not working

All pins on J4813 got connection with test points on board.
J4813 Looks ok, no corrosion etc.

Tested with 100% working trackpad and trackpad cable as well.

Any idea?

 

[2informaticos]

Check continuity between U4801 and carbon traces of keyboard flex.
You can access the traces near J4813.
In this way you can discard a bad contact inside J4813.

 

[ajdoc]

One of the pads on U4801 at WS_KBD... was not connected with board.
Solved - many thanks