I just finished assembling my latest PCB and found that I t still wasn't quite working perfectly. I found that I was missing two key resistors in my schematic that I had on my breadboard, and the hours still wouldn't advance. So I've added the two resistors. and I found that I had an error with U1 (Hours ones) not advancing U2 (hours 10's.) It works perfectly on my breadboard but I was using a pair of 2n3904 NPN transistors to form an AND gate instead of the AND gate on the schematic. I think everything should work at this point.