Sharp microwave convection oven model

Question

Sharp microwave convection oven model R-930AK. the interior light stays on all the time and the only thing that I am really able to operate is the clock and enter some commands but can not get any response. I have shut off the power to try and reset the problem and have no change. I understand that it may be an internal fuse and if so it is some how connected to the micro processers in the door latches which I guess would account for the interior light being on all of the time. What do you think?