It would help to isolate the problem before attempting a repair.

I suggest using a spare servo that you are absolutely certain works (a test beforehand is recommended) and then recreate the problem (i.e. no traverse) with the Futaba radio. Once the no-traverse problem begins, leave the power on, and unplug the DMD's "Turret" plug from the radio receiver. Next, plug the servo into the rx socket where the "turret" plug came from.

If it's a problem with the DMD or MF, the servo will work fine. If a problem with the radio system (tx or rx), you'll have no action from the servo.

If you've got a radio problem, then Dan's advice above might solve your issue.