Yep, tried that. I think I have exhausted every possibility. I sent an order to the BitMain guys for new IO boards but haven't gotten a confirmation yet. Assuming that goes through I hope that will solve the problem.
Removing the Beaglebone and then resoldering it back on seems really tough......
the BBB board just fits on using its IO pins i think - no soldering at all, just open the case and remove the central board to swap the beaglebone black.
other ideas:
1) try reseating everything. hash boards, control boards, power cabling, and the cables between the exterior ethernet/lcd and the backplane. something loose would cause issues
2) try just 1 at a time, and temporarily turn off everything else. if some other device already claimed the IP (192.168.1.99 or 192.168.1.199, i cant recall) that the S2 would not be able to communicate with the router or your PC.
3) try on another network, just in case of the above issue.
4) plug one in, then reboot your router. it may recognise and connect the device this way
5) check that there is an SD card on the BBB - in the fluke chance there isnt that would explain the issue
its unlikely 3 systems have the same issue - if you turn them on what happens? do the LEDS blink, does the LCD come on, do the lights on the ethernet port blink or light up with or without a cable inserted? Even without a web connection you should be able to boot up the device and have it display something on the LCD