NXT brick output ports not working properly My NXT brick will not let motors run.  When I download a program the motor will move forward and backward and then stop - sort of a wiggle.  Another motor will not work at all.  This happens for all three ports.  Any suggestions.
Try putting a Wait block after the motor block. Set it to wait for 5 seconds.

I think your program just terminates after one block. Please post your program next time you have a mindstorms question.