If the shielding and a motor cap did not solved the issue, then its probably not interference and probably not a power issue either, although the latter would be better confirmed with a local 5v regulator, but still. Anyway not 7905, but 7805, a lower positive value one, or some adjustable one, with a reference made by two resistors.
Try move the servo by hand just a tiny bit, maybe it has something with its feedback reference. Or try changing the signal pin and instead of that one, use some other free pin from somewhere else.
Try move the servo by hand just a tiny bit, maybe it has something with its feedback reference. Or try changing the signal pin and instead of that one, use some other free pin from somewhere else.
