I have a GE PT970SR3SS wall oven / microwave oven combo unit. The oven has two lights inside of it. Neither light socket is working. I've tested the light bulb externally in a lamp and it works fine. It does not work inside the oven however. This includes when I open the door, or, press the "Oven Light" button on the control panel. When I push the "Oven Light" button, the control panel clicks like it normally does, but the light doesn't come on.

A weird thing I noticed is that sometimes, usually when I try moving the light bulb from one socket to the other inside the oven, is that the bulb will momentarily light up for a split second, and then go dark, as I'm screwing the bulb back in. I'm not talking full brightness or anything like that, just barely enough to see the wire inside the bulb glow a little bit.

I'm a bit at a loss of where to look next. With neither light socket working I'm thinking there's something common between the two that's not working. With the momentary glow of the bulb wire when I'm screwing the bulb back in makes me think the door switch for activating the light is working fine. All of this originally started being intermittent where the lights wouldn't work at all one day, but would then work again the following day.

Any ideas of what I could look at?