I was pax in a UA 747 year before last when the (as discovered later) circulation fan malfunctioned and the cabin filled with electrical smoke.
Only problem was we were SYD-LAX and somewhere mid-Pacific at night.
The Captain made an announcement, all non essential electrics shut down, and crew plus a couple of pax who were firemen, went looking for the problem found it and isolated it.
It was bizarre as most of the pax were asleep and did not wake up, and I stood in the galley in subdued emergency lighting with a large JD and coke, making small talk with the CC, as we continued on track.
The fault was found suppressed isolated and power restored. Full marks to the Captain who managed to sound very laid back at the potential choice of flying till the wings fell off or ditching at night mid pacific, I guess the surrealism helped, however full marks to the crew in a tough corner with few choices.
Now what is it with 747s and those fans, anyone ??