It may be a glitch that prevents the daughterboard (which has the antennas) from contacting the motherboard.
Try this trick:
Leave the SIM in the phone
Plug the phone into the charger
Power off the phone
Because it is plugged into the charger, it will boot again right away.
This might allow the two boards to communicate again
You also might be looking at getting the board with the antennas replaced if the trick does not work.
Good Luck.