I got 3 Dover DMC 1 in a group and car 1 door operator stopped working and board is unresponsive to manual commands of open and close. Checked al voltages and are OK and even installed this board in car 2 and 3 and it worked. But tried the other two boards on car 1 and didn’t work, the same problem as initially.

No fuses blown, checked and replaced all relays with the other cars, and no response from the door operator.

I have a Door Fault 324.

Any clues about this case? Happy 4th of July!