sorry if this is the wrong spot but

I have a older sharp covection microwave(mid 70's) that can be used as a normal 700 watt microwave or a convection oven. today i decided to try and cook pot-pies using the convection part instead of the main gas oven. i set the machine to pre-heat too 400 degrees during which the machine let off what looked like white smoke or steam and smelled like melting insulation (maybe cause the convection part was never used before). after it got to 400 i put 3 pot pies in and set the timer for 32 minutes like the pot-pie box said. 32 minutes later the pot-pies are burnt and hollow(no gravy or anything) and like cardboard. the cardboard backing was also black in some spots. what did i do wrong. reading the manual its a 2 phase for convection. 1st is like a normal oven for pre-heating. 2nd is microwave but a fan runs to move the hot air so food cooks evenly. is there a rule of thumb for cooking food like this. like what ever time it says on the box divide it by 50 or something. i did the same thing on another microwave(non convection) i went to cook frozen bacon. put a few slices on a plastic plate with paper towels. 5 minutes later bacon is burnt plate is cracked at the bottom. i followed the cooking time of the box each time.

 

Convection cooking can take up to 25% less time than conventional depending on the food and container.

Is there a chance that the microwave is working with the elements?
You need to make sure that the fan that moves the air is working..........It is possible that was what smoked.

As far as the burnt bacon five minutes cooking time is too long and you need to use a microwave safe plate.
Until you are sure of the cooking time set the oven for a minute at a time or watch the cooking through the window.

 

I have a tabletop combo toaster/conventional/convection oven and the very broad "rule of thumb" is that when using the convection option you need to reduce the temperature setting by 25 degrees and reduce the cooking time by one-third.

I use my oven in convection mode almost exclusively. One thing I have found out is that certain things just do not cook/bake properly in a small oven regardless of the time or temperature used. I cannot use it for those "canned" cinnamon rolls, crescent rolls or biscuits. Cookies are also problematic. I need to be very careful if doing a frozen pizza. On the other hand, things like breaded shrimp, breaded chicken pieces and most things that require more than 15 minutes cooking time are done faster and more evenly in the convection oven.

 

could have been the fan cause after cooking its supposed to run to cool the inside of the microwave down after covection cooking but i didn't hear it.