@BeeBread - i'm not positive how the matrix was created, but that's probably two columns (and wouldn't be a broken column if the ones below work)
- the pcb registered these pads before switches were put in ("tested the pcb")?
- did you stress/flex the pcb when you were installing plate/switches? (this happened to me once on a different pcb)
- you can test if you broke traces by using a multi-meter and putting it into continuity mode (should make a sound when there is a connection)
• to test, one leg will have common with the adjacent switch in the column, the other leg will have common with the anode end of the diode. if you have a broken trace around the switch, you can just jumper the leg to to the adjacent soldering point.
• (be careful that you do not bridge the switch, this will act like it's constantly being pressed. and of course, DO ALL OF THIS WHILE IT'S NOT PLUGGED IN)