Well ..
That means that there is a brocken linke across the pathway of the mensioned columns ( 1,4,7,and *)/ ( 2,5,8,and 0 ) from the swithes pads on the keyboard's PCB through the connector X301 , and the Combo-Resistor Z300 to the UEM.
Of corse U need a schematic , downloade one then follow the pathways.
Check to resolder with the tip of fine solder iron the connector of the required column ,try to reflow Z300 and tell the results
