microwave waveguide cover

I have a Sharp R-3A86 microwave, recently started sparking, upon further investagation, I noticed food had driped behind the waveguide cover and got to the point it had burnt a hole completely through. Now everything i've read about these covers say there only for protecting food particles from entering the chamber,but the only cover i can find for that exact model is $35.00 plus shipping(seems expensive for such a simple part). My Question- why can't i use a waveguide cover for a different model or brand?(many i have found are $5 to $12). The microwave works fine with the cover removed(which all i read said it would) but i'm concerned that food particles will further damage microwave without a cover in place. If anyone has any insight or fixes for this problem i would be gratefull. Thank you!

ben1006, I don't know about the price in the US for these parts for these microwaves. But, I know microwaves are very cheap appliances. If this turns out the price, you would better buy a new one, is my opinion.


UNLESS: you like to try to fix it (which gives some sort of satisaction of course)