Three keys dead, how to fix?

[raffas]

I recently assembled my first board in years (hello family commitments!) and it seems three of the switchtes aren't registering.

My troubleshooting this far:

I tested all three switches with a multimeter, and I got a beep from the continuity mode when pressing down the switch. I think that means that the switch is OK, and that the soldering is OK.
I then resoldered each switch to make sure it was fine, continuity tested OK but still no keypress registered
I then unsoldered one switch and tested it, passed the continuity test
I then tested the PCB holes for the switch with the same continuity tester, and nothing. Nothing registered.

[Rob27shred]

Put some pics up of the PCB (front & back) where the offending keys are. Sounds to me like there is either a few missing diodes or a few dead diodes. The only other thing I can think of is the traces going to those switches could be damaged in some way & have been severed Given the switches themselves are fine.