How hard to make: Nanoleaf Aurora

I have 4 sets of Fluorescent bulbs fixtures in my garage ceiling and two sets went out. I found it strange that two sets went out at the same time. I'm wondering if this is a light bulb issue or a breaker. I did check the break box and did not notice none of the breaks for the garage were in the "off" position. I wanted to get some opinions here before I go and purchase 4 fluorescent bulbs, thanks.

Hi folks, So my friend has a ceiling fan in her living room that also has three lights. The screw that holds one of the light bulb sockets into the fan fell out. She tried to put the screw back in using a screwdriver, and must have hit the terminals and she said it made a pop sound, now part of the lightbulb socket turned black. We are trying to figure out whether we need to replace the socket, which I believe I can do, or if we can still use the slightly burnt socket. It sounds funny, I know, but we did put a bulb back in the socket and it still does work. But is it a hazard? See pics below of good socket and burnt socket. Thanks!