I have chenged the bulb to one I know is working, but to no avail. I have looked over the entire device and can't find a switch that might have been switched. Is there some kind of safety or trip switch that may have been tripped possible during a recent power outtage?

Is there some kind of safety or trip switch that may have been tripped possible during a recent power outtage?

Don't think so.

I have a couple Craftsman openers. Light in one on wife's side quit working. In order to stop the complaining, I moved it to my side. A few months later it started working again. Been working ever since. No switches, all controlled by circuit board. Probably cost more to repair than to buy a new opener.

Test inside the light socket to see if the unit is sending power to the bulb. I have had recent troubles like this on two Chamberleins. Turned out the material used to form the socket was so cheap and crappy that there was tiny arcing happening causing a poor electric contact with the bulb. Clean it twice and the problem always came back within a week. Coated the base of the bulb and the threads with an anticorrosive electrical paste and the problem is gone. Not saying this is your problem but check for power first.