Given the description of the error and the fact that the SD card works in the other 3 boards fine it strongly indicates that the SD card socket is either not soldered perfectly or somehow otherwise failed. If you've gone through the SD card troubleshooting link posted above and still unable to get the card to mount then we shall replace the board under warranty. Please contact E3D and initiate a warranty return. Please point them towards this thread as authorization. Sorry for the inconvenience and thank you for your patience.
