As Darryl said, I also suspect a bad 192. My thoughts:
1-Until Digitest recognizes all 3 192's, audio is not going to pass
2-What happens if you connect a 192 to the CORE card, the second 192 to the first Accel card? If that setup recognizes both 192's, then disconnect the second 192 and connect the 3rd 192. If that one still is not recognized, its must have a problem.
3-since you were inside of it, you may need to open it up again and check all connection, as well as tell us which IO cards are in which slots
4-troubleshooting is a skill that not everyone has, so its best to break things down to the minimum and then build back up slowly. With that in mind, I would test each single 192, connected to the CORE card(disconnect everything else). Once all 3 of them are known to work, THEN move on to connecting 2 or 3. I know this is tedious, but its also methodical, and that is the best approach to troubleshooting
