Disaster. Lawn mower conked out today. Luckily, we have a builder named Dennis on site, converting a farm building into a house. Now Dennis is an unusual man, in that he can do anything. I never had the slightest doubt but that he would fix my mower. He looked at it for a couple of minutes, fiddled a bit, and then hit what he referred as the solenoid with a hammer. Problem fixed.
Reminded me of an anecdote. Plumber is called to fix a broken boiler and simply hits it with a hammer, which fixes the problem. He then charges £100 for the repair. The owner of the boiler protests, informing the plumber that he's not paying £100 for one strike with a hammer. "But sir" replied the plumber "I charged you only £1 for the strike with my hammer, but I did charge you £99 for knowing just where to hit it".