They do it.
They have to inspect all the circuits that are served by that breaker looking for anomalies. They basically open everything up, poke at it, don't find anything, and then can't reproduce the problem. "What do I put?" muses the engineer, pen poised over the journey log trying to write a rectification.
"You've got a three letter abbreviation for that, don't you?" I suggest. "I'm okay if you just put 'NFF'." It stands for 'no fault found.' It sometimes means "pilot is stupid/lazy." I suppose it sometimes means the engineer is, because this one declines to write that. He documents the steps he has taken and signs off the airplane. I offer the flight to my coworker, but she doesn't want it.
Taxi out again. Backtrack to the end. Turn around. Power up. Gauges green. Brakes release, airspeed alive and rotate. Gear up. I bring back the power before we speed up and we cycle the flaps. All good. Flaps up, back to climb power and we're en route for real.
Today's destination is Red Deer. It's in Alberta, almost exactly half way between Calgary and Edmonton. It's getting dark as we arrive. I set up for 16 and then am offered a straight in for 29 and take that instead. Landing on 16 would have had me roll out and be at the apron, but now I'm not sure of the best route. We're coming up on taxiway delta but before I can check if it goes where I want, the controller offers us the backtrack. It's not actually a control tower, but an FSS, but it's one of the assertive ones that coordinates traffic rather than just telling you where other aircraft are and asking "what are your intentions?"
There's a 737 parked on the apron, but we tuck into a corner where we won't be in the jet blast when they start up again, and shut down.