I Have a sharp grill two convection oven, purchased in a Motor Home, Bounder 2000. Problem is the time display window shows only sigmented graphics. Oven seems to work, except cant see prompt for instruction.

The segmented display means either your Microwave had sustained some physical damage or you have a defective display drive I.C ( chip ). Please confirm if you are hearing the beep when you input a command on the keypad ( ignore the display ). For example place a cup of water and punch in 45 seconds and press start, If you hear the long beep after 45 seconds indicating DONE and the water feels warm/hot it means all is OK except the display driver. In all probability you will have to replace the front panel control board itself as in some countries the individual spares are not available. And that's going to cost you at least 50$ plus labor. Contact Sharp for the spare control board and since it does not require any soldering if you remove the microwave's top cover and carefully note down which wire( connector ) goes where on a piece of paper, you can fix it yourself.Good luck.

Please visit the link provided below :

http://ec1.images-amazon.com/media/i3d/01/A/man-migrate/MANUAL000072322.pdf

http://031d26d.namesecurehost.com/mwd/r820bc_bk_bw_sm.pdf

If you did not get any help from above links then you have to call the technicin from the manufacturer company.