Thanks for the great suggestions Brach. I think I found the problem. I unplugged the 2 mic/speaker daughterboards during the switch/jack troubleshooting and then plugged them back in again after we fixed that. Somehow, I got one of them reversed when I plugged them back in. I just unplugged both from the board, powered it up and bam… 5V at the left side of U5. I plugged them both in correctly, powered it back up and… you guessed it… I see digits on the LCD.
That’s good to know for future reference. If one of the 2 daughterboards is backwards, you’ll see low output at U5. Ugh… that was frustrating. I was so focused on looking at the solder joints, I completely missed the fact that one of the ribbon cables was backwards. D’oh.
In any case, thanks for your help on the switch issue. That one was legit and not just me being absent-minded.