Product review (5 stars): Correct choice...
...for the GE Spacesaver II, JEM31SF, after verifying the low-voltage transformer is still supplying power to the original (dead) controller board. Although pricey compared to the entire microwave, GE no longer sells a box with these dimensions. Instead the follow-on box, the PEM31, got nearly 1" taller, making it incompatible with custom cabinetry that may have been wrapped around the earlier model. So, you either fix your older unit or change your cabinet. This is a dilemma because the clock is ticking on yet other components like the cyclotron whereas a new unit is a fresh start, under warranty.