Can a morphtronic monster's face-down effect still activate while face-down Eg with Morphtronic Datatron does it's defense position effect still inflict 300 damage per turn if?

Yes, a Morphtronic monster's face-down effect can still activate when it is flipped face-up, as long as the conditions for activation are met. For Morphtronic Datatron, its effect to inflict 300 damage per turn when in defense position only activates while it is face-up on the field. If it remains face-down, it cannot inflict damage until it is flipped face-up and its effect is activated.