I would use a receiver pack first to make sure it IS the issue. Use a
cap or larger capacitance (uF) value along with an extra servo end you may have laying around. Just remove the signal pin (white for Futaba, yello for Hitec, etc). Or, for a few bucks more, just go to your LHS and see if they have one. They might be called something like "voltage protector" or some silly thing, but it's the same.