thermador pro gas oven not working

its model glrg364gl pro gas oven and range.20 years old.the oven wont ignite.it seems it`s been taking longer to heat up lately.now it smells like a burnt wire or something like that.i noticed the light does not work either.the range works fine.i remember replacing an oven ignitor when it was only 2 years old and the broiler has not worked for years.i know it could be a number of things but any ideas would be helpfull.thanks