I lent a Nikon D700 with Nikon 24-70 f/2.8 attached to someone recently
Moral of the story is, never lend a nice camera out with someone attached to the lens.
I set about repairing the Rivetess' Yashica sort of electronic 35mm. She'd dropped it 18" onto soft grass. Called the service department of Dixons or Currys - whatever, and was told it had to be serviced at c half the new price.
"Oh, but I'm an ex techie, can't you help?"
"No. Too dangerous. High voltages in there." (flash.)
"Oh, oh, but I worked on old PYE sets with a hard 9kv EHT. Please help."
"No, piss off." Well, words to that effect.
The battle was on.
Careful notes and a piece of paper with each screw poked through a diagram of the case. Lots of poking and prodding of the worst bit of lashed up circuitry I've ever seen. Found a ribbon cable with wires so thin they were barely visible.
"Please send me the ribbon cable - you know, techie to techie. Like in the old days."
"Ooooo...the ribbon cable?" he said, thoughtfully. "No, not sending one."
I said something . . . can't remember what, and hung up.
Put wires in that looked like powerstation cables by comparison. And it worked! Tested it again and got a hell of a belt from the flash circuit.
Then some bastard invented digital cameras.