Crackling/sizzling sound My GE spacemaker makes a crakling/sizzling sound as it cooks...otherwise it works fine. Is it safe? I have young children and am concerned. A year or 2 ago our tile installer accidently turned it on with nothing in it and one of the plastic peices melted, causing metal to be exposed...then it stopped heating entirely, we got both issues fixed (seperately) and we had a year of nothing... Is this "something"?? It appears that there may be some black ash on the inside door frame (as you look at it from the outside) but it doesn't make sense, it is minimal and it is never warm. Please someone help me...Should I just buy a new machine?

If you're hearing a crackling noise and don't see any sparks, you may have a magnetron that is arcing inside the waveguide. Once this arcing occurs, in some cases, replacing the magnetron may not be enough to fix the problem. There was also a noted problem with some models where the stirrer motor shaft inside the waveguide would arc when the magnetron was energized. This too, caused damage inside the waveguide. If the internal walls of the waveguide become damaged it cannot be repaired and the unit must be scrapped. The waveguide has a special coating to help propagate waves of RF energy. If the walls are damaged due to arcing this special coating gets burned off and will continue to arc even if a new magnetron is installed. This will eventually lead to magnetron failure and potentially cause a fire inside the oven. I would think seriously about looking into another unit if any of this may be occurring in your oven. Better to play it safe, especially with small children. I hope you find this advice helpful. PS A new magnetron can run as high as $250.