Funny, but true. A helicopter, squadron unnamed to protect the guilty, had a peculiar fault; namely, the generator would not work when switching from external to internal power. Multiple generators swapped and still wouldnt work. One electrician figured out that one quick hit with a hammer reactivated the magnetic field and got the generator going.
The helicopter was permanently assigned to new pilots.
did you ever put some oil/fluid on a rag and act like you were cleaning up a drip while said pilot was doing preflight?