This should have been an easy fix so I must be missing something really simple.
I was going to re-seat my playfield inserts on my Gottlieb Rollercoaster to have them level on playfield.
Moved light bulb under playfield to get to insert and the lamp socket broke (base of socket just spins).
It apparently shorted something and there was a brief spark and all playfield lights went out (backbox lights are still on).
First thing I thought was fuse. Checked 10 amp fuse, it was good.
Checked fuse holder, also seems ok.
Got another lamp socket and made sure base was soldered to ground. (See attached)