Holy ****!  I found a defect on the PCB and fixed it.  I need Oddforge or Zefyr to confirm this is a good fix.  
I spent the whole night using a multi-meter to see if I could figure anything out.  I noticed that on most rows, the bottom end of the diodes on the same row connects to each other, except the HJKL; row.  And I checked that they do connect between ; L K J H, but not between " and ;.  

At first I thought the via was plugged and causing the problem, but when I looked closer, the trace is actually disconnected (at the red rectangle).  I jumped and connected these points and looks like all the keys are working now.   

I am glad I fixed it.  But I am mad that the PCB is defective, and caused me so much grief...
Can I get a replacement PCB?