My Amana built-in microwave MVH210E has started to make little explosive noises (single noise each time, seems to come from behind push-button area, ends micro-waving). Is it dangerous (either as to microwave exposure or as to fire hazard) to continue using it until it just dies, or should I act to replace it now? It may be more prone to do this when a boiling pot below it on the stove is throwing off a lot of steam. Thanks.