GE Microwave Spacemaker oven, Model JVM240

Question

I noticed that surface light bulbs were not working, so I replaced each one (they were blown). After replacing bulbs I depressed keypad for surface lights controls, but lights will not light. I also noticed that vent fan will not operate when depressing keypad control for vent fan.All other features and microwave work and operate.I turned main fusebreaker for microwave off and then on, but did not cure problem.Any ideas?Thanks