Here is some old mechanics "wisdom" if found whilst trawling through the wunderful world of the web.
You only ever need to carry 2 things in your tool roll in order to fix any problem:
WD40.....and a roll of Duct tape.
"If it should move and doesn't: use the WD40."
"If it does move but shouldn't: Use the duct tape."
(popcorn)
Haha.
:dash1:
If it moves train it,
if it doesn't calibrate it,
It is written down, revision control it,
If it is not, it never happened.