The Engineers Dilemma:
Once you get off your butt to go see what the problem is, the problem will mysteriously solve itself for the time being.
Source: Worked in local television News Production. We would regularly call on the engineers for the problem to fucking resolve itself by the time they showed up. Always made me feel real stupid.
Was an on/off service technician/engineer for the last 20 years and can confirm. Many times I’d get a fault call just to arrive, pull out my screw driver and the issue simply resolves itself. It’s as if it knows things are getting serious and it’s afraid to be taken apart.
I worked on air traffic control radios, about a third of the time the entry in the maintenance log was “could not duplicate problem”.
The fun entries were “adjusted relays with screwdriver”. Now, for those who don’t know, relays generally don’t have a screw adjustment, but if you tap on the outside casing, they often unstick.
Good 'ol percussive maintenance.
The true key to percussive maintenance, knowing where to hit and how hard.
I’ve seen people try to replicate good percussive maintenance and fail due to not knowing where and how hard to hit things. Those were expensive mistakes.