On Oct 19, 7:02*pm, "diggerodell" wrote:
Inside my microwave is a small 3x5" opening which is covered by a 3 x 5"
piece of thin shinny cardboard. *At one time, the four corners of the
cardboard fit snugly into four small slots, so that it barely covered the
full opening. *Now those four corners have become broken and worn, allowing
the cardboard to slip 1/4" below the top opening. *Will this affect the
performance or safety of the microwave? *If so, can I replace the cardboard
with a piece of non-shinny cardboard?

Thanks.
digger

Is the shiny side around the light bulb that illuminates the interior
of the oven? If so, replacing it with plain cardboard will be ok, but
the light level will be much less. If it is anywhere else, the shiny
side may be electrically conductive and part of the microwave system
and should not be replaced with plain cardboard. Why not use duct
tape to hold the original in place?