Chosen Solution
My grandson got the Nerf Mega Mastodon for his birthday today. It stopped shooting and making any noise about an hour after he opened it. We have replaced the batteries with brand new ones again but it still does not work. Do you have any suggestions?
open the jam door. Even if it’s not jammed, open and close this. It will start working again
Jam door switch is usually the culprit. Open the case by undoing the 19 or 20 odd screws, remove the jam door, wiggle the little black rubber coated switch. Put it back together without the jam door so you can access the switch if it happens again.