The mummy coffin door on my monster bash opens when the mummy mode starts, but with any vibration from the pops or ball, it slams shut. I think it's supposed to stay open until the end of the mode. If I touch the door I can feel it vibrating from the effect of the solenoid behind, but clearly it's not holding the rod enough to stop the door closing. Has anyone seen this behaviour before and got any idea how I can fix it?